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MADRONO

A WEST AMERICAN JOURNAL OF BOTANY

VOLUME XXX 1983

BOARD OF EDITORS Class of:

1983—ROBERT W. CRUDEN, University of Iowa, Iowa City DUNCAN M. PorRTER, Virginia Polytechnic Institute and State University, Blacksburg

1984— Mary E. BARKWorRTH, Utah State University, Logan Harry D. THIERS, San Francisco State University, San Francisco

1985—STERLING C. KEELEY, Whittier College, Whittier, CA ARTHUR C. GIBSON, University of California, Los Angeles

1986—AMY JEAN GILMARTIN, Washington State University, Pullman ROBERT A. SCHLISING, California State University, Chico

1987—J. RZEDOWSKI, Instituto Politecnico Nacional, Mexico DoroTHY DOUGLAS, Boise State University, Boise, ID

Editor—CHRISTOPHER DAVIDSON Idaho Botanical Garden, P.O. Box 2140, Boise, ID 83701

Published quarterly by the California Botanical Society, Inc. Life Sciences Building, University of California, Berkeley 94720

Printed by Allen Press, Inc., Lawrence, KS 66044

ll

Reid Moran began botanizing the world when he was very young and had a back-yard Dudleya collection when no more than ten years old. He did his undergraduate work at Stanford and then went on to Cornell to work on Dudleya with Jens Clausen. This was in the early 40s, when some war or another broke out, and Reid joined two of his cohorts as enlistees in the airforce. They ended up in the 15th Airforce flying raids over Jugoslavia. In a stroke of luck, neither good nor bad, Reid got zapped in mission no. 1 and was found by some of Tito’s partisans tangled in the top of a tree he was trying to identify. After a lengthy walk he made his way back to safety in Italy and finally flew back to the USA. It should be noted, though, that the return flight was mysteriously routed through a number of North African bases, at each of which Reid managed to nab a few specimens. When discovered back at Cornell, he was in the herbarium pressing some of his acquisitions—in full uniform. His well-known, unique sense of humor has affected many of his colleagues, and the noteworthy collection section of this journal has never fully recovered from his famous “I found it there then” contribution.

He finished his PhD at Berkeley with Lincoln Constance and after a brief time as a UC extension instructor, moved to the San Diego Museum of Natural History.

Reid is certainly one of the finest field botanists in the West (sensu lato), and his knowledge of the northwest Baja California flora and that of the islands is unparalleled. We take great pleasure in dedi- cating volume 30 to him.

ill

TABLE OF CONTENTS

AHART, L. (see Taylor, M. S.)

ARDEMA, D. S. (see Johnson, F. D.)

BAKER, J. L. (see Davis, C. B.)

BALDWIN, B. G., and S. N. MARTENS, Noteworthy collections of Opuntia bi- gelovit, Mentzelia puberula, Nemacaulis denudata var. gracilis, and Penste- INOW PS CULO OSPCCL VOUS, see 2h Aces eee en ee

BARBOUR, M. G. (see Yoder, V.)

BARTEL, J. A. and J. R. SHEVOCK, Dudleya calcicola (Crassulaceae), a new species from the southern Sierra Nevada _______-_____-__-_------------

BECVAR, J. E. (see Freeman, C. E.)

Boyp, R. S., Jackrabbit herbivory and creosote bush (Larrea) reproduction ____ (see also under Yoder, V.)

BRUNSFELD, S., S. Caccio, and D. HENDERSON, Noteworthy collection of Par- VE US SUC ICOUE CO LGU oe ata oa ee Se a ae ec tee Sa ee EI (see also under Lackschewitz, K.)

BRUNSFELD, S. J. and F. D. JOHNSON, Noteworthy collections of Salix candida, S. maccalliana, and Eriophorum viridicarinatum _______-_--_-__-------------

Caicco, S., J. CIVILLE, and D. HENDERSON, Noteworthy collections of Astrag- alus leptaleus and Penstemon procerus _-.._.2--2----22422222 220-2 ee (see also under Brunsfeld, S.)

CAIN, D. J., ANDH. T. HARVEY, Evidence of salinity-induced ecophenic variation In cordgrass (Spaviinajoosa Uri.) 222.22

CARTER, A. M. Review of Imagenes de la flora Quintanarroense (by O. Teélez hh) ee ea ee Eo eee 2 ee gee eee PRP ae BEEP er eee CAME V I a erly Le (see also under Rudd, V. E.)

CASTAGNOLI, S., GREG DE NEVERS, and R. D. STONE, Noteworthy collections of Brickellia knappiana and Selinocarpus nevadensis _______-_-------------_-

CHOLEWA, A. F. and D. HENDERSON, Noteworthy collections of Lesquerella kingii, Astragalus kentrophyta var. jessiae, and Gilia polycladon _________- (see also under Goodrich, S.)

CIVILLE, J. (see Caicco, S.)

Cope, E. A., Chemosystematic affinities of a California population of Abies UVES A012) ee ee eee Es aeRO hE Se Ne PER tenn an oi ETO

DAVIDSON, C., Review of Genera of the western plants (by W. T. Batson) ____ Review of A flora of Waterton Lakes National Park (by Job Kuijt) __--____

Davis, C. B., A. G. VAN DER VALK, and J. L. BAKER, The role of four macro- phyte species in the removal of nitrogen and phosphorus from nutrient-rich water.in a prairie marsh, lowa. ...-...2. 22225222225 heed ee

DE NEVERS, G. (see Castagnoli, S.)

ECKENWALDER, J. E., Review of Atlas of United States trees. Volume 6. Sup- plement. (by ici dlittle $y)" 5-22 eee ee

ERTRIER, Be Notes on Jvesvachvpard 5 ee

Evert, E. F., A new species of Lomatium (Umbelliferae) from Wyoming _____-

EwInNG, A. L. and J. W. MENKE, Reproductive potential of Bromus mollis and Avena barbata under drought conditions _______________________-___-_----------

FERREN, W. R., Jr. and S. A. WHITMORE, Suaeda esteroa (Chenopodiaceae) a new species from estuaries of southern California and Baja California ____

FORCELLA, F., Review of Basin and range (by J. McPhee) ______-__-__-------__-

FREEMAN, C. E., W. H. REID, and J. E. BECVAR, Nectar sugar composition in some species of Agave (Agavaceae) _______________________-_____---------------+---

FRYXELL, J. E., A revision of Abutilon sect. Oligocarpae (Malvaceae), including anew species trom Mexico «22.2222 te ee

GILL, S. J. and J. D. MASTROGUISEPPE, Noteworthy collection of Lomatium PERO CHOSE UE aces Tet Nala es sO nee Oe tae ee ee

64

259

64

50

198

129

63

110 66 197

133

131 257 143 159

181 198

153

84

259

GILMARTIN, A. J., A male sterile morph in Lycium fremontii (Solanaceae) from Bajan@ aitonniay SU 222tee te Sat ee ee 2 ae ee eee See ee

GoopRIcH, S., D. HENDERSON, and A. F. CHOLEWA, Noteworthy collections of Astragalus gilvifiorus and Hackelia davisi —_......2232-2222-

Gray, J. T., Competition for light and a dynamic boundary between chaparral AMCUCOASEAIUS AG Cas CHUL) we mas .ueemenen Wie ae So pd a a, ee Se ee eee

HARPER, K. T., Review of Flora of the Central Wasatch Front, Utah (by L. Amnow bs Albeewand Ac WyCkKOlh) 4222.22 -222.. eee

HarRVvEY, H. T. (see Cain, D. J.)

HARVEY, S. J. (see Forcella, F.)

HENDERSON, D. (see Goodrich, S.; Cholewa, A. F.; Caicco, S.; Brunsfeld, S.; and Lackschewitz, K.)

HENRICKSON, J., A new Chihuahuan Desert rose (Rosaceae) ___-__-_--_--___-___-

JOHNSON, F. D. and D. S. ARDEMA, A disjunct population of Ribes sanguineum (Grossulaniace ae) yim i alien ee ee ee

JOHNSON, F. D. and S. J. BRUNSFELD, Noteworthy collections of Salix candida ATGMC 1) O0 TAU Gere ne = ee atrena) 2a ee ce eee ee ee (see also under Brunsfeld, S. J.)

KELLEY, W., Noteworthy collection of Cryptantha mensana ________-------------_-

KRUCKEBERG, A. R. and J. L. MorRISON, New Streptanthus taxa (Cruciferae) bromni@ AlNTOrMI ay te 2 ee oe ge ee ee

LACKSHEWITZ, K., D. HENDERSON, and S. BRUNSFELD, Noteworthy collection Ld CIO Y LOL GIN UTS x ene alae NY act ee ae ee

LEE, G. J., Noteworthy collection of Phacelia vallicola ______________-_-_-----_--

Lesica, P., Noteworthy collections of Erigeron flagellaris and Papaver kluanen- IES een eee ie Me net ei le ee er eee as mean Ae oe oe

MARTENS, S. N. (see Baldwin, B. G.)

MASTROGUISEPPE, J. D. (see S. J. Gill)

MEINKE, R. J., Mimulus hymenophyllus (Scrophulariaceae), a new species from

the Snake River Canyon area of eastern Oregon ______---------------

MENKE, J. W. (see Ewing, A. L.)

Morrison, J. L. (see Kruckeberg, A. R.)

Nakal, K. M., Is Dudleya parva (Crassulaceae) truly in San Luis Obispo COUT Ly eee a ah ad NN Me ch ar natn a

NESOM, G. L., New species of Calochortus (Liliaceae) and Linum (Linaceae) from POPU EN MV LG SNC Or eo eee rr ek et ee ee ee ee

NeEsoM, G. L. and W. A. WEBER, A new woolly-headed, monocephalous Erig- eron (Asteraceae) from Montana ____________--_8

POHL, R. W., Review of The grasses of Baja California, Mexico (by F. W. Gould ZEW alles SIN R08 Gc (1!) Mens eee ee as eR eee cotee eee MRE OE MEMES aCe a ent ee Ae

PorTER, D. M., Review of William Robinson 1838-1935. Father of the English fowercarden: (boy WG Aller) to ee

POWELL, A. M., Perityle (Asteraceae), new species and notes ___------------- |

PRAY, T. R. (see Wagner, W. H., Jr.)

REES, J. D. (see Vovides, A. P.)

REID, W. H. (see Freeman, C. E.)

RIGGINS, R., Noteworthy collection of Pedicularis dudleyi _____-__-_-_--_---___-

Rupp, V. E. and A. M. CARTER, Acacia pacensis (Leguminosae: Mimosoideae), a new species from Baja California Sur, Mexico ____-_--_-----------

RUSSELL, E. W. B., Pollen analysis of past vegetation at Point Reyes National Seashore. California, 22222255 See eee

SANDERS, A. C. (see Vasek, F. C.)

SCHOOLCRAFT, G. D., Noteworthy collections of Antennaria flagellaris and Cau- VOTUCHEES EI) Of ese ae es ee ee ee ee ee

SHEIKH, M. Y., New taxa of western American Eryngium (Umbelliferae) ______

SHEVOCK, J. R. (see Bartel, J. A.)

129

63

43

199

226

191

259

258

230

64 179

196

147

63

176

129

SMITH, A. R. (see Wagner, W. H., Jr.)

STATEMENT of ownership, management, and circulation for 1982...

STEWART, J. G., Lemanea (Rhodophyta) in mountain streams of southern Cali- 10) a 11: coe a ae ee ara pa aR Ia Dsptrens e868 DOES ea I ee

STONE, R. D. (see Castagnoli, S.)

STROTHER, J. L., Pionocarpus becomes lostephane (Compositae: Heliantheae): a SVMODSIS fas) ass! oe gee es Sg ee ee et ee

TAVARES, I., Review of A field guide to mushrooms and their relatives (by C. Boothcand Fl. HH. Burdsall: ri )\2.222 2. ee a ee

TayLor, M. S. and L. AHART, Noteworthy collection of Moenchia erecta ____

TODSEN, T. K., A new variety of Perityle staurophylla (Asteraceae) from New IMIGXIC Ot 2 seen es chen foes 5 cen sie De ee ee ee ee

TURNER, B. L. and G. TURNER, A new gypsophilic species of Galium (Rubiaceae) from north-central Mexico_2..2... 2.3.22 ee

VAN DER VALK, A. G. (see Davis, C. B.)

VASEK, F. C. and A. C. SANDERS, Distribution of Polygala acanthoclada

VINYARD, W. C. (see Wharton, R. A., Jr.)

VOVIDES, A. P. and J. D. REES, Ceratozamia microstrobila (Zamiaceae), a new Species from: San Luis Potosi, Mexico’ 2. .2 2.22.2 ee

WAGGONER, J. P. III (see Yeaton, R. I.)

WAGNER, W. H., Jr., A. R. SMITH, and T. R. PRAY, A cliff brake hybrid, Pellaea bridgesit X mucronata, and its systematic significance____-------_--_-___

WAGNER, W. L., Noteworthy collections of Arenaria stricta, Galium emeryense subsp. emeryense, and Lepidium oblongum

WEBER, W. A. (see Nesom, G. L.)

WELLS, H., Hybridization and genetic recombination of Circium californicum and €. occidentale (Asteraceae: Carduceae) _..__._. 2

WHITMORE, S. A. (see Ferren, W. R., Jr.)

WHARTON, R. A., Jr. and W. C. VINYARD, Distribution of snow and ice algae in -westerm North Amerita_..-.22..-.22. 22-5 ee

WOODWARD, R. A. (see Yoder, V.)

YEATON, R. I., R. W. YEATON, and J. P. WAGGONER III, Changes in morpho- logical characteristics of Pinus engelmannii over an elevational gradient in Durango: Wiexico:: 2-222 = a ee On Se oe Aw

YovER, V., M. G. BARBouR, R. S. BOYD, and R. A. WOODWARD, Vegetation of the Alabama Hills region, Inyo County, California ____--_______-___________-

SUPPLEMENT

BUCKINGHAM, N. M. and E. L. TiscuH, Additions to the native vascular flora of the Olympic Peninsula, Washington ) {2222-2 ee ee HUNTER, K. B. and R. E. JOHNSON, Alpine flora of the Sweetwater Mountains, Mono Cotimty, Caltioniy ao 5 6c pe oe ee ee JOKERST, J. D., The vascular plant flora of Table Mountain, Butte County, Cali- |G) 0h tk eS eae eID eRe eee Oe NL ee Nae te ee Ree wince ey aoe se 2 PALMER, R., B. L. CORBIN, R. WOODWARD, and M. BARBOUR, Floristic checklist for the Headwaters Basin area of the North Fork of the American River, Placer County Californias 2.82. -<2222. A es ee SCHAAK, C. G., The alpine vascular flora of Arizona ____-------------------------- SCHLISING, R. A. and E. L. SANDERS, Vascular plants of Richvale Vernal Pools, Butte: County. Cali ornia, 2.2.2 ele SWEARINGEN, T. A., The vascular flora of the Muddy Mountains, Clark County, INGA a pra et she ae et eh ee ee

129

126

12

201

168

118

S89

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Va Peas N ed

Sie

ADRONO

VOLUME 30, NUMBER 1 JANUARY 1983

Contents

POLLEN ANALYSIS OF PAST VEGETATION AT POINT REYES NATIONAL SEASHORE, CALIFORNIA, Emily W. B. Russell 1 HYBRIDIZATION AND GENETIC RECOMBINATION OF CIRCIUM CALIFORNICUM AND C. OCCIDENTALE (ASTERACEAE: CAR-

DUCEAE),

Harrington Wells 12 A NEw GYPSOPHILIC SPECIES OF GALIUM (RUBIACEAE) FROM

NORTH-CENTRAL MExiIco, B. L. Turner and Gayle Turner 31 PIONOCARPUS BECOMES IOSTEPHANE (COMPOSITAE: HELIAN-

THEAE): A SYNOPSIS, John L. Strother 34

CERATOZAMIA MICROSTROBILA (ZAMIACEAE), A NEW SPECIES

FROM SAN LuwIs Potosf, MExIco,

Andrew P. Vovides and John D. Rees 39 COMPETITION FOR LIGHT AND A DYNAMIC BOUNDARY BE-

TWEEN CHAPARRAL AND COASTAL SAGE SCRUB,

John T. Gray 43 EVIDENCE OF SALINITY-INDUCED ECOPHENIC VARIATION IN

CORDGRASS (SPARTINA FOLIOSA TRIN.),

Daniel J. Cain and H. Thomas Harvey...» 50 “om 7 HS uf On ¥ an , NOTEWORTHY COLLECTIONS “ 63 CALIFORNIA 63 IDAHO ! SS 4 63 MonTANA-IDAHO \ Mode 64 REVIEWS ~ LIBRARIES _-* 66 MO eects ote ANNOUNCEMENTS 65, 67

STATEMENT OF OWNERSHIP, MANAGEMENT, AND CIRCULATION 68

WEST AMERICAN JOURNAL OF BOTANY

A

PUBLISHED QUARTERLY BY THE CALIFORNIA BOTANICAL SOCIETY

MADRONO (ISSN 0024-9637) is published quarterly by the California Botanical Society, Inc., and is issued from the office of the Society, Herbarium, Life Sciences Building, University of California, Berkeley, CA 94720. Subscription rate: $25 per calendar year. Subscription information on inside back cover. Established 1916. Second-class postage paid at Berkeley, CA, and additional mailing offices. Return requested. POSTMASTER: Send address changes to Susan Cochrane, California Natural Diversity Data Base, Calif. Dept. of Fish & Game, 1416 9th St. Rm. 1225, Sacramento, CA 95814.

Editor—CHRISTOPHER DAVIDSON

Idaho Botanical Garden P.O. Box 2140 Boise, Idaho 83701

Board of Editors Class of:

1982—-DEAN W. TAYLOR, University of California, Davis

RICHARD VOGL, California State University, Los Angeles 1983—ROBERT W. CRUDEN, University of Iowa, Iowa City

DUNCAN M. PORTER, Virginia Polytechnic Institute and State University,

Blacksburg

1984—Mary E. BARKWORTH, Utah State University, Logan

Harry D. THIERS, San Francisco State University, San Francisco 1985—-STERLING C. KEELEY, Whittier College, Whittier, CA

ARTHUR C. GIBSON, University of California, Los Angeles 1986—AMyY JEAN GILMARTIN, Washington State University, Pullman

ROBERT A. SCHLISING, California State University, Chico

CALIFORNIA BOTANICAL SOCIETY, INC.

OFFICERS FOR 1982

President: ‘WATSON M. LAETSCH, Department of Botany, University of California, Berkeley 94720

First Vice President: ROBERT ROBICHAUX, Department of Botany, University of California, Berkeley 94720

Second Vice President: VESTA HESSE, P. O. Box 181, Boulder Creek, CA 95006

Recording Secretary: ROBERT W. PATTERSON, Department of Biology, San Francisco State University, San Francisco, CA 94132

Corresponding Secretary: SUSAN COCHRANE, California Natural Diversity Data Base, Calif. Dept. of Fish & Game, 1416 9th St. Rm. 1225, Sacramento, CA 95814

Treasurer: CHERIE L. R. WETZEL, Department of Biology, City College of San Francisco, 50 Phelan Ave., San Francisco, CA 94112

The Council of the California Botanical Society consists of the officers listed above plus the immediate Past President, ROBERT ORNDUFF, Department of Botany, Uni- versity of California, Berkeley 94720; the Editor of MADRONO; three elected Council Members: LYMAN BENSON, Box 8011, The Sequoias, 501 Portola Rd., Portola Valley, CA 94025; JoHN M. TucCKER, Department of Botany, University of California, Davis 95616; CHARLES F. QUIBELL, Department of Biological Sciences, Sonoma State Col- lege, Rohnert Park, CA 94928; and a Graduate Student Representative, CHRISTINE BERN, Department of Biology, San Francisco State University, San Francisco, CA 94132.

POLLEN ANALYSIS OF PAST VEGETATION AT POINT REYES NATIONAL SEASHORE, CALIFORNIA

EMILY W. B. RUSSELL Department of Geology, Rutgers University, Newark, NJ 07102

ABSTRACT

Pollen analysis indicates major vegetational changes near Wildcat Lake, Point Reyes National Seashore, California, in the last millennium. Changes in the relative propor- tions of grass and shrub pollen both before and after colonization imply that the pro- portions of grassland and scrub vegetation were not constant even before European colonization. Near the top of the sediment core the ratio of grass to shrub pollen in- creases. The simultaneous appearance of pollen of introduced plant species allows this level of the diagram to be dated historically at about 1850 A.D. Thus this increase in grasses may be correlated with increased grazing. A shift from abundant Alnus pollen to Myrica and Salix near the bottom of the core is interpreted as the result of a landslide that changed local drainage.

Agricultural and logging practices obscure precolonial vegetational patterns in the New World. Because the patterns are probably caused primarily by interactions of climate, soil and topography, their recon- struction is of considerable interest to ecologists. For example, the Mediterranean type of vegetation that characterizes western California has a fairly short history of active exploitation, generally less than 150 years. Near the coast, extensive short grass pastures are interspersed with shrubby vegetation, occasional small, bunch-grass prairies, and deciduous or coniferous woodlands. The mountain ridges parallel to the coast are mainly forested with Pinus spp. or Pseudotsuga menzie- sii, and many valleys east of these ridges in the northern and north- central parts of the state contain Sequoia sempervirens (Munz and Keck 1959, Ornduff 1974).

Probably the most active cultural exploitations are grazing and ur- banization, which have nearly obliterated the natural vegetation of coastal prairie, dominated by grasses such as Deschampsia holcifor- mis, Calamagrostis nutkaensis and Festuca californica. Grazing has also modified coastal scrub, dominated by shrubs such as Rhus diver- stloba, Rubus ursinus, Artemisia californica, Baccharis pilularis, Lu- pinus spp., and members of the Rhamnaceae (Howell 1949, Munz and Keck 1959, Barbour et al. 1973, Ornduff 1974, Heady et al. 1977, Grams et al. 1977). The present study concerns the history of an area north of San Francisco, Point Reyes National Seashore.

Previous studies of the past and present coastal vegetation have reached conflicting conclusions about its history, as well as its present

MADRONO, Vol. 30, No. 1, pp. 1-11, 28 January 1983

2 MADRONO [Vol. 30

composition. North of Point Reyes to the Oregon border, Burtt-Davy (1902) found a variety of species, e.g., Erodium moschatum, Bromus rigidus, Hordeum leporinum and Centaurea melitensis, invading pas- ture land in 1900. Based on observations of fenced-off areas, he de- duced that the original forage plants had been perennial bunch grasses, chiefly Danthonia, Stipa and Melica. Wild oats (Avena fatua) and Evrodium displaced these very palatable species in the 19th century as grazing pressure increased. Continued grazing led to dominance by Hordeum jubatum, Sitanion hystrix and Bromus mollis by 1900. He saw the presettlement landscape as consisting of prairies and “hard” chaparral of Adenostema fasciculatum, Ceanothus cuneatus and other chaparral species (Burtt-Davy 1902).

At Point Reyes, Baccharis pilularis dominates the coastal scrub, with at least 25% cover (Grams et al. 1977). Floristic differences in the scrub correspond with differences in exposure: on north-facing slopes Polystichum munitum is second in importance, whereas on south- facing slopes Rhamnus californica is second. Grams considered all but one of the sites to be “undisturbed” because they were not being grazed, but he did not outline the history of prior disturbance.

Also at Point Reyes, Elliott and Wehausen (1974) studied distur- bance effects on deep, sandy soil in level, grazed sites. The native bunch-grass Deschampsia caespitosa formed denser cover in a plot ungrazed for six years than in plots continuously grazed by cattle. The growth difference may suggest a shift to prairie vegetation and is interpreted by Elliott and Wehausen as indicating that prairie was the dominant type of vegetation prior to grazing. However, Baccharis pilularis had the second highest cover on the plot, and Rumex ace- tosella, an introduced perennial, ranked fourth. The less heavily grazed plot had more Deschampsia caespitosa than the other, but also more Baccharis pilularis. Their study thus does not give a clear indication of the pre-grazing vegetation, whether it was grassland or scrub.

One hypothesis suggested by these earlier studies (e.g., Burtt-Davy 1902, Elliott and Wehausen 1974, Grams et al. 1977), which is tested here, is that there were major shifts in the proportion of grassland to coastal scrub taxa in the vegetation from pre-Columbian time to the present. This hypothesis would be supported by pollen records indi- cating changes in the ratio of grass to scrub pollen, representing a change in the ratio of prairie to scrub vegetation. The main shrubs to be considered are members of the Asteraceae, e.g., Baccharis pilularis and Artemisia spp., members of the Rhamnaceae, and Rhus diver- stloba. The direction and timing of changes in the pollen record would suggest patterns of succession in the past.

STUDY AREA AND METHODS

Point Reyes Peninsula, located at 38°N, 123°W, is separated from the mainland by the San Andreas rift zone. The base rock of Creta-

1983] RUSSELL: VEGETATIONAL HISTORY OF PT. REYES 3

ceous granodiorite crops out in the northeastern part of the Peninsula and on the western tip. In most of the area the Miocene Monterey Formation, mainly bentonitic shale, overlies the granodiorite (Gallo- way 1977, Howard 1979). The dip of the Monterey Formation par- allels the slope of the terrain, resulting in extreme landslide suscepti- bility in view of the bentonitic shale, high rainfall on the seaward slopes, and earthquakes (Clague 1969). These landslides have pro- duced a landscape of steep breakaway scarps, large hummocks, and frequent lakes where slumps have dammed stream valleys (see Gal- loway 1977).

The climate is Mediterranean, with wet, cool winters and cool, foggy summers with little precipitation. The mean maximum temper- ature in July is about 16—-18°C, whereas the mean minimum temper- ature for the same month is 11°C. Mean maximum temperature in January is 13°C, and the mean minimum is 5—7°C. Mean annual pre- cipitation is 58—67 cm, with almost no rain falling in July-August and the maximum falling in December—February (Elford 1970). Fires in the coastal scrub are common and may alter the vegetation (Wells 1962).

Soil type maps of the Point Reyes Peninsula are not available, but generally the soil in the study area appears to be shaley clay loam over shaley clay, about 50-100 cm deep (Grams et al. 1977). There are also local shale outcrops with very shallow soil.

Wildcat Lake is located near the southwest tip of the Point Reyes National Seashore. A landslide estimated at 70,000—100,000 years B.P. blocked a valley drainage, created the lake, and left a scarp on the lake’s northeast side (Fig. 1) (Clague 1969). Later slides of lesser extent left piles of debris, especially on the southeast side of the lake. The ages of these slides have not been determined.

Two sediment cores were taken in 1978 by Roger Byrne and Jeffrey Loux. One, about 50 cm long, was obtained with a 10 cm diameter plastic tube for retrieval of relatively undisturbed shallow samples. The second, 300 cm long, was obtained with a 5 cm diameter Living- stone piston corer, near the site of the first. The coring site was located in a deep part of the lake away from the inlet and outlet at the north- east end (Fig. 1).

Samples were taken from the short core at 1, 20, 30, 35, 40, 45, and 50 cm. From the long core, samples were taken at 25 cm intervals from 50 cm below the surface to 275 cm, plus one at 55 cm. All samples were prepared according to standard procedures for concentrating pol- len and were mounted in silicon oil (Faegri and Iversen 1975). An average of 11,850 Lycopodium spores added to each sample served as a control for comparing relative concentrations of taxa in the sediment. For each sample at least 200 pollen grains were counted at 430.

Pollen of species locally associated with wet conditions, Alnus, Sa- lix, Myrica, and Typha, constituted a large proportion of the fossil assemblage in many samples. Changes in these obscured changes in

4 MADRONO [Vol. 30

inlet

O 60 120 | ee | m

N

Fic. 1. Bathymetric map of Wildcat Lake, including coring site (X) (modified from Clague 1969).

the less common grass and shrub taxa. Lack of radiometric dates for the sediment and major changes in pollen influx made the use of “absolute” pollen diagrams inappropriate. Therefore pollen percents were calculated on two totals, that of the wetland species as a percent of the total and that of the remaining taxa as a percent of these taxa. This differentiation distinguished changes in local drainage patterns

1983] RUSSELL: VEGETATIONAL HISTORY OF PT. REYES 5

from changes in upland vegetation. Pollen of the wetland species was generally 30% or more of the total, indicating that it was largely locally produced. Upland pollen was blown in from varying distances (Erdt- man 1969, Faegri and Iversen 1975).

To study fire history, the area covered by charcoal particles was determined on the same slides that were used for pollen counts. Only black charcoal in which cellular structure (e.g., spiral wall thickenings or bordered pits) was visible was tallied. The area covered by such a piece was determined using a reticle with unit area = 150 wm’. The total area of charcoal for each sample was divided by the number of control grains (Lycopodium spores) counted on the same traverses to estimate charcoal concentration. A minimum of 10 control grains, or 10 traverses (at 430), was counted at each level.

On 8 April and 2 June 1979, the most obvious taxa with the greatest apparent cover were noted along 12 and 17 km of trails, respectively. On 8 April, the most conspicuous members of the scrub community were Artemisia californica, Lupinus spp., Rhus diversiloba, Pteridi- um aquilinum and Polystichum munitum. Common species noticed blooming were Lupinus spp., Sanicula arctopoides on shallow soil, Eschscholzia californica, Iris douglasii, Ranunculus sp., Heracleum lanatum and Rumex acetosella. In the canyons where streams flowed to the ocean there were small, salt-stunted Pseudotsuga menziesii and some Quercus agrifolia. Higher up above the first range of hills Pseu- dotsuga grew much larger. Near Bass Lake and Lake Ranch, south of Wildcat Lake, were Salix sp., Pseudotsuga menziesii and Alnus rubra.

Near Wildcat Lake, Baccharis pilularis and Rhamnus californica were common. Rumex acetosella and Plantago lanceolata formed most of the vegetation on small paths. Alnus rubra grew thickly along the inlet stream, and Salix sp. at the outlet. Salzx also provided dense cover in a gully at the south end of the lake. Trees on the uplands in the vicinity of the lake were Umbellularia californica, Quercus agri- folia and Pseudotsuga menziesi1. The only area covered mainly with grasses in the valley around Wildcat Lake was southeast of the large slump southeast of the lake.

RESULTS

Pollen data are given in Fig. 2. Major changes occur between levels 225 and 150 cm in the wetland species. The most salient changes are the decline in Alnus and Typha pollen from 200 cm to 150 cm and the concomitant increase of Myrica and Salix. Notable changes in “non- aquatic” pollen occur at 150-125 cm and around 50-55 cm. Near 150 cm, aquatics appear to stabilize, whereas Sequoia and Artemisia pol- len percentages decline and grass pollen percentage increases. Slightly higher in the core, percent pollen of the Rhamnaceae decreases as that

6 MADRONO [Vol. 30

nN MmoOmMaos Oo ie) N @ (o>) KR =] be c} o DOKWON ire) KR Ry x R i rm He S Zin N ANAND N N i) N N N ie) Nn N g a ° oa) » 8 1D404/q “by oo : je) ° 5) i im 5) ° jor n S ig 2a eo a uM snuly Q, a = oo 6S Tis 6 Co ~ o_o mS ° ~ ot S No 3 te o o fia *oy Dowkw u fo) [wins ° =] | ial 40 5 = XID JOS &0 ss oS wnipoig fe) + O}D{OadUD|; OBoyUDId ) fe) Ga nN ~ : Ge io) re) aD29D0q ie) ~ _— io) xawny t Q o 68 7 ~ apaoDidy ~ — nn fe) oO (auids y61y) = ce apaoDIaysV = a: D18]wesly © DISIWaylY rr or oe ¢ ee avadDuWDYY . = O+ OQ, -—c ete 5 0) snoiand ~ 4 2) fan] opnsvopnesd p de wee pl a ° al >) £2) = on pionbas : ° N snuld o (w2) 4y4deqd fo ° ° co) © 2 0 a io (o) ire) oO wo KR — —s N N N

‘aqueous’ pollen.”

1983] RUSSELL: VEGETATIONAL HISTORY OF PT. REYES if

50

100

150

200

depth (cm)

250

O 20 40 60 80 100 20

2] : -2 — = area of charcoal ((um) /n0. control grains x10 -- = no. pollen grains/no. control grains

Fic. 3. Charcoal concentration in samples compared with pollen concentration in the same samples.

of the Apiaceae increases. Above about 50 cm a general increase in Pinus and Quercus pollen is accompanied by a decrease in Asteraceae and possibly in Poaceae. The 50 cm level is also marked by the ap- pearance of the introduced European pasture weeds Plantago lanceo- lata and Rumex acetosella and an occasional grain of Erodium.

The concentration of charcoal is compared with concentration of pollen in Fig. 3. An increase in the concentration of charcoal where a similar increase does not occur in the concentration of pollen probably indicates the occurrence of a fire or fire period. Concomitant increases of pollen and charcoal are caused by changes in sedimentation, which would affect both similarly. Fires are thus indicated at 0, 40, 175, and 225/¢m,

The ratio of grass pollen to shrub pollen (Fig. 4) ranges from 1.2:1 to 0.3:1, with a mean of about 0.8:1. The low corresponds with a peak

8 MADRONO [Vol. 30

50

100 150 € ae) = 200 a o no] 250 300 0 20 40 60 80 100 120 140 160 180 200 220

no. grass pollen grains/no. scrub pollen grains x 10

Fic. 4. Ratio of grass (Poaceae) pollen to scrub (Asteraceae, including Artemisia, Rhamnaceae, Rhus) pollen.

in Myrica pollen at 150 cm. This fluctuating ratio becomes slightly higher (1.0:1) and fluctuates more above 50 cm.

DISCUSSION

The most precise date in the pollen core is the first appearance of pollen of introduced taxa, Rumex acetosella and Plantago lanceolata, at 50 cm (Fig. 2). Historical data place this near 1850 A.D. The core was taken in 1978, indicating a sedimentation rate of 50 cm/128 yr, or 0.39 cm/yr. Extrapolation of this rate to sediment below this point gives a minimum estimate of 1275 A.D. for the age of the sediment. Erosion accelerated by grazing, which increased the input of sediment to the lake, plus compaction at lower levels make this a very conser- vative estimate of the age of the bottom of the core.

The variations in the ratio of grass pollen to shrub pollen (Fig. 4) support the hypothesis that the ratio of grassland to scrub has changed in the past. Fluctuations in the proportion of grassland seem to have occurred before European settlement of the area. It appears likely that the precolonial landscape contained a mixture of prairie and chaparral vegetation, as suggested by Burtt-Davy (1902). The areas studied by Elliott and Wehausen (1974) and Grams et al. (1977) may represent naturally occurring temporal and spatial variation in the mosaic of vegetation.

1983] RUSSELL: VEGETATIONAL HISTORY OF PT. REYES 9

The low ratio of grass to shrub pollen at 150 cm, which corresponds with a peak in Myrica pollen, may be associated with a fire, because Myrica spreads rapidly after fires (Howell 1949). Very high charcoal counts at about 175 cm (Fig. 3) show the possibility of a fire at that level. The fire may have been followed by the spread of Myrica and fire-stimulated scrub species, and a temporary low period of grass growth.

That grass pollen is generally less common than the scrub species cannot, by itself, be taken as evidence that scrub was more common than prairie. Differential production and dispersal of pollen alone may have caused this difference if the scrub species produce more pollen per unit area than the grasses. However, the increased fluctuations in the ratio after European settlement, and the higher grass pollen in some samples, suggest that increased exploitation of the land by graz- ing increased grassland at the expense of shrubs.

The pollen evidence of wetland species (Fig. 2) raises another issue. It appears that sudden changes have occurred in local drainage over the period sampled by this core. These changes, probably associated with landslides, have occurred since the formation of the lake. Above 200 cm the dramatic decrease in alder pollen strongly indicates a re- duction in the habitat of alder, which in this area is generally along streambanks. One may surmise that at this time there was a local landslide or slump that slowed the flow of water in a nearby stream such that the alder no longer had a suitable habitat locally. Then the increased swampy area was invaded by Salix, which presently forms a nearly impenetrable thicket at the outlet of the lake near the north end. The simultaneous decline of Typha pollen could be related to slump filling of the shallow littoral site formerly occupied by Typha. Myrica may have invaded the disturbed habitat formed by the slump debris.

Pseudotsuga, which grows on the ridge east of the lake, is repre- sented in the pollen record with a maximum of six percent. This con- firms Erdtman’s (1969) statement that Pseudotsuga pollen has very low powers of dispersal.

After European settlement, the relative amounts of Pinus and Quer- cus pollen increased and, at least at one point, the amount of Sequoia pollen declined sharply. A decline in Asteraceae and Poaceae pollen is associated with the increases in Pinus and Quercus pollen. This might correspond with the type of grazing landscape described by Laperousse in 1786, in which a few trees were left in cattle pastures for shade (Lapérousse 1937). The grazed Poaceae and Asteraceae pro- duced little pollen, whereas the trees may have produced more copi- ously than when in a thicker stand. Scrub, consisting largely of Ar- temisia and Rhamnaceae, persisted outside the pastures (Laperousse 1937, Beechey n.d.). The sudden drop in Sequoia pollen and subse- quent recovery above 30 cm probably indicates the heavy logging of

10 MADRONO [Vol. 30

this species in the early 20th century. The peak of Salix pollen at 50 cm may suggest that Judge Shafter, who owned this land in the late 19th century, tried to use Salix as a living fence in places, as did ranchers in the southern part of the state (Fabian 1869).

The vegetation in this area presents a basic pattern in which the non-arboreal pollen remains near 40% of the total. The most important upland taxa are Poaceae, Asteraceae (including Artemisia) and Se- quoia, the latter blown in from a distance. However, shifts in the relative abundances of these pollen taxa indicate changes in the vege- tation during the centuries preceding European settlement in addition to changes caused by European settlement. Causes of the pre-Colum- bian changes are unknown, but topographic disturbances in the area are indicated by sudden shifts in taxa whose distribution is related to changes in local drainage. We may thus see a superposition of topo- graphic disturbance on a system adapted to the local climate, soils and topography.

ACKNOWLEDGMENTS

The research for this paper was carried out at the University of California, Berkeley, in 1979, while I was a Research Fellow in the Department of Geography. Roger Byrne suggested the topic and provided invaluable logistical assistance, as well as discussion of ideas. Jeffrey Loux collected and processed the sediment as part of term paper research in 1978. Richard T. T. Forman, T. Webb III and G. Batchelder provided helpful comments on earlier versions of this paper.

LITERATURE CITED

BarRBour, M. G., R. B. CralG, F. R. DRYSDALE, and M. T. GHISELIN. 1973. Coast- al ecology: Bodega Head. Univ. California Press, Berkeley.

BEECHEY, F. W. n.d. An account of a visit to California, 1826-—’27. Reprint. The Grabhorn Press, CA.

BurTT-Davy, J. 1902. Stock ranges of northwestern California. Notes on the grasses, forage plants and range conditions. USDA Plant Industry Bull. no. 12.

CLAGUE, J. J. 1969. The landslides in the southeast part of Point Reyes National Seashore. M.A. thesis, Univ. California, Berkeley.

ELFORD, C. R. 1970. The climate of California. Jn Climates of the States, 2:538- 594. Natl. Oceanic and Atmospheric Admin., US Dept. Commerce. 1974.

ELLIOTT, H. W. III and J. D. WEHAUSEN. 1974. Vegetational -uccession on coastal rangeland of Point Reyes Peninsula. Madrono 22:231-238.

ERDTMAN, G. 1969. Handbook of palynology. Hafner Publ. Co., NY.

FABIAN, B. 1869. The agricultural lands of California. H. H. Bancroft and Co., San Francisco.

FAEGRI, K. and J. IVERSEN. 1975. Textbook of pollen analysis. 3rd. ed. Hafner Press, NY.

GaALLoway, A. J. 1977. Geology of the Point Reyes Peninsula, Marin County, Cal- ifornia. Cal. Div. Mines and Geol. Bull. 202.

GRAMS, H. J., K. R. MCPHERSON, V. V. KING, S. A. MACLEOD, and M. G. BARBOUR. 1977. Northern coastal scrub on Point Reyes Peninsula. Madrono 24:18-—24. Heapy, H. F., T. C. Foin, M. M. HEKTNER, D. W. TayLor, M. G. BARBOUR, and W. J. Barry. 1977. Coastal prairie and northern coastal scrub. In M. G. Bar- bour and J. Major, eds., Terrestrial vegetation of California, p. 733-760. Wiley—

Interscience, NY.

1983] RUSSELL: VEGETATIONAL HISTORY OF PT. REYES ila

Howarp, A. P. 1979. Geologic history of Middle California. Univ. California Press, Berkeley.

HowELL, J. T. 1949. Marin flora. Univ. California Press, Berkeley.

LAPEROUSSE, J. F. DEG. 1937. Le voyage de Lapérousse sur les cotes de |’Alaska et de la Californie (1786). Historical Documents, Institut francais de Washington, Cahier X. Johns Hopkins Press, Baltimore.

Munz, P. A. 1959. A California flora. Univ. California Press, Berkeley.

NATIONAL PARK SERVICE. 1976. Natural resources management plan and environ- mental assessment: Point Reyes National Seashore. Washington, DC.

ORNDUFF, R. 1974. California plant life. Univ. California Press, Berkeley.

WELLS, P. V. 1962. Vegetation in relation to geologic substratum and fire in the San Luis Obispo County Quadrangle, California. Ecol. Monogr. 32:79-103.

HYBRIDIZATION AND GENETIC RECOMBINATION OF CIRSIUM CALIFORNICUM AND C. OCCIDENTALE (ASTERACEAE: CARDUCEAE)

HARRINGTON WELLS

Faculty of Natural Sciences, University of Tulsa, Tulsa, OK 74104

ABSTRACT

Sympatric populations of Cirsium californicum (series Neomexicana) and Cirsium occidentale (series Occidentalia) were studied. The populations occurred as a set of colonies along Happy Canyon Road, Santa Barbara County, California. Morphological data, pollen fertilities, and controlled crosses all support the conclusion that the two taxonomic species studied are one biological species at the Happy Canyon site, that no sterility barriers exist to prevent gene recombination, and that hybrid and recombinant forms compose almost the entire Happy Canyon Cirsium population. However, micro- geographic differentiation of recombinant morphological types was observed to be cor- related to ecological habitats. Protein electrophoretic data support the conclusion that habitat-correlated electrophoretic and morphological phenotypes have a genetic basis rather than having been environmentally induced. The data suggest that the two species have hybridized in the studied population and that differentiation may be occurring along new lines.

The genus Cirsium is in the family Asteraceae, tribe Carduceae (Thistle). Taxonomically, there are between 200 and 250 described species in the genus, of which 34 occur in Washington, Oregon, and California (Howell 1968). Approximately 30 of the West Coast species occur in California (Munz and Keck 1959). The classification of the California species of Cirsium has been changed several times in this century (Jepson 1925, Munz and Keck 1959, Howell 1968, Munz 1974). All of these authors have suggested that the taxon Cirsium is evolu- tionarily complex and in need of further study before its evolutionary dynamics can be completely understood.

Taxonomic division of Cirsium into species is made difficult in part by the presence of morphologically intermediate individuals. Hybrid- ization of Pacific Coast species has been suggested between approxi- mately 23 species pairs involving 19 species (Howell 1968). Hybrid- ization occurs not only between closely related species, but also between some morphologically dissimilar species (C. fontinale and C. querce- torum, and C. brevifolium and C. utahense). It appears that the genus is taxonomically complex and that the difficulty of species delimitation may result from rapid, present-day evolution.

Despite the several revisions of the genus, C. californicum and C. occidentale have always been considered distinct; they have always been placed in separate series and have never been reported to hy-

MADRONO, Vol. 30, No. 1, pp. 12—30, 28 January 1983

1983] WELLS: HYBRIDIZATION IN CIRSIUM 13

bridize. Acceptance of the current ranking of C. californicum and C. occidentale is based on the apparent historical continuity of classifi- cations and agreement of taxonomists (Jepson 1925, Munz and Keck 1959, Howell 1968, Munz 1974).

This study presents data on the interactions of C. californicum and C. occidentale occurring sympatrically in a single well-defined geo- graphic population. Two questions are addressed. First, what degree of biological distinctness has been reached between the species C. californicum and C. occidentale in the study area? Second, what, if any, geographically related genetic differentiation exists in the studied population? Answers to these questions may lead to a greater under- standing of the processes of evolution in nature and ultimately of the phylogeny of Cirsium.

MATERIALS AND METHODS

Species description. C. californicum branches from the base up- wards. The plants have a strong taproot. Basal leaves develop in a rosette and can be up to 3 dm long and 1 dm wide. They are oblan- ceolate, deeply lobed, and have slender spines. Caulescent leaves are shorter, and have reduced lobes and spininess distally. Leaf blades are glabrescent and green above, and white arachnoid-wooly below. The capitula of C. californicum usually occur solitarily on the ends of long slender peduncles. The heads are up to 6 cm in diameter, and up to 4.5 cm long. The involucre is bowl] shaped, making the capit- ulum hemispheric. Phyllaries are spine tipped and spreading above. Flowers are tubular and white, sometimes pink (Table 1).

C. occidentale is an herbaceous, taprooted plant up to 3 m tall. Basal leaves form a rosette up to 8 dm in diameter from which a single thick stem arises. Branching occurs only on the upper stem and forms the inflorescence. Leaves are purple to reddish with light cottony pu- bescence, deeply lobed, and very spiny. Deep lobing and spininess occur from the leaf base to the distal tip. The branching pattern forms a panicle. Flowers in the heads are compressed into a vertical cylinder by the phyllaries. Phyllaries are constricted to form a narrow neck, are spine tipped, and have cottony webbing. Flowers are all tubular, perfect, and red (Table 1).

The population. The population studied was composed of C. cali- fornicum and C. occidentale individuals in an essentially linear array of 42 disjunct colonies along Happy Canyon Road to the summit of Figueroa Mountain, Santa Barbara County, California. In this respect it resembled the linear stepping stone model of population structure (Kimura 1953). The population was dispersed over approximately 19 km and elevation ranged from approximately 600 to 1100 m. Four habitat types were traversed by the Happy Canyon roadway with its associated Cirsium population: chaparral, valley grassland, southern

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“CHONILNOD) ‘T ATEVY,

16 MADRONO [Vol. 30

DISTRIBUTION OF COLONIES

GRASSLAND OAK GRASSLAND OAK CHAPARRAL PINE No. | FOREST No.2 FOREST FOREST FOREST GRASSLAND No.3

Fic. 1. Map of colony and habitat distribution for Happy Canyon Cirsium popu- lation.

oak woodland, and yellow pine forest (Munz and Keck 1959). Colonies of the Happy Canyon Cirsium population were distributed such that 41% were in the chaparral region; 38% in the grassland areas; 21% in the oak woodland, and none in the pine forest (Fig. 1). A survey of the terrain away from the road revealed that Happy Canyon Cir- sium occurred only in roadside colonies.

Elevation increased most rapidly in the chaparral area (400 m) and least in the nearly level grassland regions. Three separate grassland areas existed, isolated from one another by large areas of other habitat types. Grasslands No. 1 and No. 2 were spatially close and at ap- proximately the same elevation, whereas grassland No. 3 was isolated from both grasslands No. 1 and No. 2 by large areas of other habitat types and was at a significantly higher elevation.

Even though Czrsium colonies do not extend into the native, un- disturbed vegetation in the study region, habitat type is an indicator of and modifies, the overall environment. That is, the species com- posing the surrounding community are a result of the environment of a region, and may be a better measure of the environment than can be obtained through direct measurements, because even if many en- vironmental parameters are measured at many locations, one still does not know the relative weighting of the factors (Unger 1836, Schimper 1898, Warming 1909, Drude 1913, Odum 1959, Ovington 1962, Dau- benmire 1968, Krajina 1969, Mueller-Dombois and Ellenberg 1974). Thus, it is as a reflection of the environment, rather than extensive interaction of Cirsium with species in the community, that I refer to habitat type.

Colonies of Cirsium consisted of discrete patches of individuals oc-

1983] WELLS: HYBRIDIZATION IN CIRSIUM Li

curring at densities between 1 and 4 plants per m?. When Cirsium occurred on both sides of the road at a location they were considered a single colony. Approximately 200 flowering individuals occurred in each colony, except the grassland colonies, which ranged between 500 and 1000 flowering individuals. The only colonies with fewer individ- uals were the three chaparral colonies adjacent to the pine forest hab- itat, and the isolated grassland colony No. 1 in Fig. 1. The study was carried out from 1976 to 1979, and collections were made in 1977.

Morphological data and analysis. A random sample of each colony was obtained by collecting plants along a line transect. Two hundred thirty-two plants from the Happy Canyon population (an average of 5.5 plants per colony) were chosen from the collections, using a ran- dom numbers table, for numerical taxonomic analysis. In addition, 15 plants used in crosses and chosen for their similarity to C. californi- cum, C. occidentale, or for their intermediacy, were included in the morphological analysis. Finally, included were 12 herbarium speci- mens of C. californicum, 11 of C. occidentale, 2 of apparent hybrid identity (Santa Cruz Island and Tule River), a specimen of C. vulgare, and a specimen of C. tioganum, all identified previously by other collectors. Specimens were all from the University of California at Santa Barbara Herbarium (UCSB 7229-7235, 7239-7244, 6454, 6456, 6459, 8440, 15330, 18245, 22061, 22291, 24011, 24291, 24320, 28865, 31527, 32531). The C. californicum and C. occidentale herbarium specimens were used as references for species phenotypes. By using specimens identified and reviewed by other systematists, personal biases were eliminated in establishing references.

Thirty-five morphological characters were used in the numerical taxonomic analysis (Table 1): 28 metric and 7 plus-minus (+ pubes- cence = dense; + color = red; + corolla lobe shape = spatulate). Characters were chosen that showed variability in the population and that were obtainable from herbarium specimens as well as living ma- terial. Characters were measured on plants of similar age, and on organs of comparable development.

All characters were ranged between values of O and 1 before Q matrix numerical analyses, so that they all had equal weight (Sneath and Sokal 1973). Morphological data analysis was performed by the distance diagram technique (Wells 1979), cluster analysis (NTSYS Program), and principal coordinate analysis (Gower 1966), all of which operate on Q type matrices. Principal component analysis (SPSS Pro- gram) and means and their standard errors were obtained from R type matrices. Analyses were performed on an IBM 360/75 computer. The generalized n row by m column hypergeometric version of the general exact test (Wells and King 1980) and the chi-square test were used to test for a relationship between habitat type and morphological form, as defined by the principal coordinate analysis. The spatial (11.5 km)

18 MADRONO [Vol. 30

and elevational (400 m) isolation between Cirsium of grassland No. 3 and No. 1 & 2 allowed testing of the hypothesis that habitat correlated selection had occurred, rather than formation of a cline or selection by an environmental factor not related to habitat.

The alternative hypotheses were considered by testing for differ- ences between the Cirsium of grassland areas 1 & 2 and 3, between the Cirsium of grassland 1 & 2 and chaparral, and between grassland 3 and chaparral Cirsium using the chi-square and general exact test statistics. If a cline existed or selection by a factor actually uncorrelated to habitat occurred, then Cirsium in grassland areas 1 & 2 and 3 should be different because they are isolated and at different elevations. How- ever, grassland Cirsium from areas 1 & 2 and 3 should not differ, but each should be different from chaparral Cirsium, if habitat determin- ing factors are causing differentiation. Finally, silhouettes of stem leaves, inflorescences, and peduncle leaves provide a graphic display of the variation within the Happy Canyon population.

Sterility barriers. The presence of sterility barriers to gene recom- bination was tested by observing pollen fertility, and by ovule devel- opment in controlled crosses, as well as by morphological analysis. Ownby et al. (1975) have studied C. californicum and C. occidentale cytologically and demonstrated that both have 2n = 30 chromosomes throughout their range. Percent pollen fertility was tested on the 274 plants used for morphological analysis. A flower was removed from each of the dried specimens, 200 grains sampled and stained with lactophenol blue to determine percent fertility (Radford et al. 1975). Fertility barriers were also tested by crosses between species, within species but between individuals, between species types and hybrid types, and by bagging. An analysis of variance on the arcsine V frequency of developed ovules was used to determine significance of differences. Finally, 1160 capitula, each from a separate plant (a sample independent of those used for morphological analysis), were dissected and the percentages of developed ovules recorded.

Protein electrophoretic data and analysis. Seeds removed from the inflorescences collected to determine the field ovule development of heads were germinated and grown to small rosettes. Leaves of the rosettes were removed and used (while still fresh) for electrophoresis in the isozyme analysis. Slab acrylamide gel electrophoresis was used to separate isozymes following the techniques described by Wells and Wells (1980). The enzyme loci studied include leucine aminopeptidase (LAP), alkaline phosphatase, acid phosphatase, malate dehydroge- nase, lactate dehydrogenase, and “general protein.” Isozyme stain for- mulas are those of Shaw and Prasad (1970) and Johnson (1975). Results were grouped according to habitat type. The hypergeometric version of the general exact test (G.E.T.) and the chi-square test were used to determine whether significant differences occurred in genotype fre-

1983] WELLS: HYBRIDIZATION IN CIRSIUM 19

SCALE

Fic. 2. Distance diagram of Happy Canyon and herbarium reference individuals. Cirsium occidentale and C. californicum reference specimens fall into two distant clus- ters according to species. Cirsium vulgare and C. tioganum are depicted as distinct species by their position. Happy Canyon individuals exist as a continuum of points from the C. occidentale to the C. californicum herbarium specimens as would be ex- pected if hybridization and backcrossing are occurring. A = C. californicum, O = C. occidentale, ® = Happy Canyon Cirsium individuals, V = C. vulgare, T = C. tioga- num, and X = Cirsium herbarium specimens of questioned species identity. Individuals used in crossing experiments: R = red flowered plants resembling C. occidentale, W = white flowered plants resembling C. californicum, and P = pink flowered plants inter- mediate in floral characteristics.

quencies between colonies grouped by habitat type. Both the general exact and chi-square tests were also used to test whether habitat re- lated selection was actually occurring by comparing grasslands 1 & 2 and 3, and to chaparral Cirsium, as was done with the morphological data. Genotype frequencies rather than allele frequencies were used because random mating could not be assumed, and because they are more conservative (sample size 2) than inferred allele frequencies (Spiess 1977).

RESULTS AND DISCUSSION

One biological species or two? Morphological variation in the pop- ulation, pollen fertility within the population, and seed set in experi- mental crosses were examined to determine whether C. californicum and C. occidentale are true biological species in the Happy Canyon population. Morphological data are displayed in a distance diagram (Wells 1979) in Fig. 2; a phenogram from a cluster analysis is given as Fig. 3; scatter diagrams of the first three axes of a principal coor- dinate analysis (Gower 1966) in Figs. 4, 5; as means and their standard

20 MADRONO [Vol. 30

PHENOGRAM

0 ° ee hh ee _ : : lh Lo 0 °

Ae Se ee

Hh Aoi “hose Coreaceo me kai Nei het) ee MCE (aR es ayy Dsccececeese!

Fic. 3. Phenogram from unweighted pair group method using arithmetic average linkage cluster analysis. The lack of large differences in the cluster levels indicates a gradation of morphological forms, as would be expected through hybridization and backcrossing. Herbarium specimens: O = C. occidentale, C = C. californicum, T = C. tioganum, V = C. vulgare, and X = Cirsium herbarium specimens of questioned species identity.

errors in Table 1; and as stem leaf, inflorescence, and peduncle leaf silhouettes in Figs. 6, 7, 8.

Distance diagram. The herbarium specimens identified as C. cali- fornicum and as C. occidentale fell into two distinct clusters along species lines (Fig. 2). Cirsium vulgare and C. tioganum herbarium specimens fell outside the inner semicircle and close to the outer semi- circle centrally in the diagram, as should distinct species. Also note that two herbarium specimens of hybrid identity (Santa Cruz Island; and Tule River, Tulare County, California) fell at an intermediate “hybrid” position on the distance diagram.

The study population was a continuum of forms, ranging from C. californicum to C. occidentale within both circles (Fig. 2). Of 247 plants of the Happy Canyon sample, only two fell outside the inner semicircle of the distance diagram, as might be expected if backcrosses frequently occur and neither parental line contains all alleles of some genes for extreme character values (Grant 1964). All evidence from the distance diagram is consistent with the hypotheses that only one biological species was being studied in Happy Canyon, that no sterility barriers existed, that hybridization and backcrossing are common, and that Happy Canyon Cirsium may be treated as one genetic population.

The distance diagram also includes the individuals used in crosses that will be analyzed later. Some C. occidentale individuals used in crosses appear to be backcrosses, but as Fig. 2 depicts, examples of C. californicum and C. occidentale as defined by the reference indi- viduals were difficult to find.

Cluster analysis. One sees no distinct clusters, but rather a gradation of cluster levels in Fig. 3. If there had been a barrier to initial hy- bridization and subsequent backcrossing, two distinct clusters should have been produced by the cluster analysis, corresponding to C. cal- ifornicum and C. occidentale, respectively. The cluster analysis, like the distance diagram, supports the interpretation that a single genetic

1983] WELLS: HYBRIDIZATION IN CIRSIUM 21

I

Fic. 4. Principal coordinate analysis axes I and II. No distinct clusters occur as expected when hybridization and backcrossing occurs. Herbarium specimens: O = C. occidentale, A = C. californicum, T = C. tioganum, V = C. vulgare, and X = Cir- stum herbarium specimens of questioned species identity. Individuals used in crosses: R = C. occidentale, W = C. californicum, and P = intermediate. ® = Happy Canyon Cirsium individuals.

population was being studied with no sterility barriers between mor- phological types.

Principal coordinate analysis. Next, individual morphological vari- ation was studied through principal coordinate analysis. The first three axes account for 64% of the total variance; the first 13, for 93% of the total variance. Depicted as Fig. 4 are axes I and II, and as Fig. 5 are axes I and III. If barriers exist to gene exchange and recombination, the principal coordinate analysis should depict just two isolated clus- ters of points: one containing all of the C. californicum reference in- dividuals, and the other all of the C. occidentale reference individuals. Axes I and II reveal no isolated cluster of points; a continuum exists between C. occidentale grouped reference points and those of C. cal- ifornicum. Figure 4, therefore, gives evidence that only one genetic population exists.

Figure 5, which displays axes I and III of the principal coordinate analysis has new information, but still supports the conclusion that one biological species was being studied and that there were no bar-

0) MADRONO [Vol. 30

“2

Fic. 5. Principal coordinate analysis axes I and III. Two distinct clusters occurred corresponding to the positive and negative poles of axis III. However, reference indi- viduals of both C. californicum and C. occidentale occurred in both clusters, and within a cluster a continuum of forms exists between the species types. Therefore, some factor (e.g., environmental selection) other than species has caused differentiation of two re- combinant forms. Herbarium specimens: O = C. occidentale, A = C. californicum, T =C. tioganum, V = C. vulgare, and X = Cirsium herbarium specimens of ques- tioned species identity. Individuals used in crosses: R = C. occidentale, W = C. cali- fornicum, and P = intermediate, ® = Happy Canyon Cirsium individuals.

riers to hybridization. Clearly, two clusters occur in Fig. 5, one on the positive side of axis III and the other on the negative. However, ref- erence individuals of both species, and of both species types used for crosses, occur in both clusters. Also, in both the positive and negative clusters there is a continuum of forms spanning the space between the reference specimens of both species. Thus, the morphological evidence still supports the theory that there is but one biological species being studied, and that recombinant forms constitute the majority of the individuals of the studied population. However, there appears to be grouping of recombinant phenotypes into two clusters by some force (genetic or developmental response). Principal coordinate analysis of axes II and III (available from the author) gave results similar to axes I and III. Axis three still caused separation into two clusters, and each cluster still had both reference species included.

Principal component analysis. A principal component analysis (R matrix) was performed in an attempt to describe the characteristics that separate individuals into the two clusters in the principal coor-

1983] WELLS: HYBRIDIZATION IN CIRSIUM 23

dinate analysis (Q matrix). Unfortunately, the component analysis (available from the author) did not greatly simplify the data space. The first eight principal component axes (64% of the variance) were studied. Only one cluster was produced in the analysis, a result that is consistent with hybridization but does not characterize individuals in the two principal coordinate clusters.

Means and standard errors. The means and their standard errors of each of the 35 characters for individuals classified as C. californi- cum, C. occidentale, and for individuals of each of the principal co- ordinate clusters were examined next for differences and relations in characteristics between members of the two coordinate clusters (Table 1). In the positive cluster, 34% of the character means are not signif- icantly different from C. occidentale (within 2 standard errors) but are significantly different from C. californicum, and 26 percent do not differ from C. californicum but do differ from C. occidentale. The negative cluster has 31% of the character means non-differentiable statistically from C. occidentale but different from C. californicum, and 23% not different from C. californicum but different from C. occi- dentale. Forty-three percent of the characters have means significantly different between the plus and minus clusters. Individuals of the plus cluster have arachnoid pubescence on both peduncle and stem leaves, have long peduncle leaves, and wider inflorescence bracts, as does C. californicum, while having the number of leaf lobes, spine lengths on leaves, stem diameter, pappus length, and corolla lobe shape similar to C. occidentale. The negative cluster has these characters similar to the opposite parent, though not always as extreme. The minus cluster also has involucre shape like C. occidentale, but the plus cluster is quite variable in this character. Thus, the principal coordinate clusters are hybrid individuals composed of recombinant characteristics.

Silhouettes. Gestalt description of morphological variation of Czr- stum in Happy Canyon is supplied by the silhouettes of stem leaves, inflorescence, and peduncle leaves (Figs. 6, 7, and 8). Recombinant types exist in the leaf silhouettes (Fig. 6). Again, a complete gradation of forms is seen in capitula (Fig. 7), and in the peduncle leaves (Fig. 8).

In the morphological analysis of the Happy Canyon population, organ silhouettes and a wide variety of numerical methods all suggest that, although the population includes two recognized taxonomic species, it is composed primarily of hybrids and backcross forms.

Pollen fertility. Sixty-seven percent of the individuals sampled had pollen fertility higher than 90%, and 85% of the population had pollen fertility higher than 80%. Unless the individuals with low fertility are all F, or some other specific type hybrid, no evidence emerged to indicate a sterility barrier. Apparently only one genetic population exists.

24 MADRONO [Vol. 30

rea | | lcm

Fic. 6. Stem leaf silhouettes. Typical C. occidentale leaf is depicted lower right, and typical C. californicum leaf upper and lower left. A gradation of forms existed from one species to the other species.

californicum

occidentale

A distance diagram (Fig. 9) may reveal a clustering of infertile hy- brid individuals. If found, such clustering would suggest that two biological species, rather than one, were being studied. Individuals with low fertility were uniformly distributed across the morphological spectrum. Thus, pollen sterility does not restrict gene migration and recombination in the Cirsium population studied.

Ovule development. Another test for sterility barriers was that of ovule development per head in experimental crosses (Table 2). Those capitula that were bagged rarely produced any developed ovules. All cross-pollinated inflorescences produced a markedly greater proportion of developed ovules than did bagged plants. There are two hypotheses about out-crossing ovule development that should be tested. The first is that one or more types of crosses between different individuals (oc- cidentale X occidentale, californicum X californicum, occidentale X californicum, occidentale X hybrid, californicum X hybrid, or hy- brid X hybrid) will have significantly higher or lower percent ovule development than the other crosses. The other hypothesis is that cross- es between individuals of the same species (occidentale < occidentale, and californicum X californicum) will have significantly higher or lower

1983] WELLS: HYBRIDIZATION IN CIRSIUM Z5

lcm

‘t+ +

occidentale californicum

californicum

Fic. 7. Inflorescence silhouettes. Typical C. occidentale form is shown by the upper left inflorescence, and typical C. californicum forms by the lower left and center sil- houettes. A gradation of forms existed from one species to the other.

{++ lcm

ek f 42 y

¥

occidentale

californicum

Fic. 8. Peduncle leaf silhouettes. Typical C. occidentale form is depicted by the upper right silhouette and typical C. californicum forms by the lower right two leaves. A wide variety of recombinant forms existed, a few of which are shown.

26 MADRONO [Vol. 30

—— af + O ss) eo as. | SCALE

Fic. 9. Distance diagram of reference and Happy Canyon individuals. Symbols refer to percent pollen fertility of the individuals. Sterility was randomly distributed throughout the scatter. Thus, there was no evidence of a sterility barrier to gene re- combination. ® = pollen fertility >95%, A = pollen fertility between 90% and 95%, O = pollen fertility 830% to 90%, and A = pollen fertility below 80%.

percent ovule development than crosses between species, species X hybrid, or hybrid x hybrid. These two hypotheses were tested by use of a one-way analysis of variance on the arcsine transformed data (arcsine V frequency developed ovules per head). Neither test showed a significant difference (Table 2), so the null hypothesis that all types of crosses are equally fertile cannot be rejected.

Finally, developed ovule frequency in capitula of controlled lath house crosses was compared to the frequency of developed ovules per head in the field. In nature, mean percent developed ovules was 20.1 (S.D. = 25.9 n = 1160 flowers dissected). The non-developed ovaries were small and shriveled as if fertilization had not occurred. It may be that the efficiency of the pollen vectors in transporting pollen limits ovule development, as shown by Levin (1968) for Lithospermum. De- veloped ovules of capitula in experimental crosses were also about 20%.

The principal coordinate analysis separated Cirsium individuals into two distinct groups based on morphological characters. These clusters do not correspond to the taxonomic species. Could different environ- ments have caused the observed phenotypic variation? This possibility was examined by asking whether a correlation exists between the de- fined habitat types and morphological phenotypes (Table 3). The null hypothesis is that the number of individuals in a cell is dependent only on the frequency of individuals sampled from a habitat and that the distribution of phenotypes is identical in each habitat. The null hy-

1983] WELLS: HYBRIDIZATION IN CIRSIUM 27

TABLE 2. OVULE DEVELOPMENT FREQUENCY IN EXPERIMENTAL CROSSES.

Bagged plants: x = 0.00097; n = 18. (Mean frequency) Cross pollinated: Frequency developed ovules, x = 0.2117; n = 18 Cross (group)

1

califor- 4 G nicum 2 3 califor- 5 califor- califor- hybrid occidentale nicum occidentale nicum Cross # = nicum hybrid occidentale Hybrid Hybrid occidentale 0.1875 0.1739 0.1250 O.2127 0.5650 0.1429 2 0.2698 0.1633 0.2500 0.2000 Oy2222 0.1020 5 0.2500 0.2413 0.1515 0.1875 0.1892 0.1765

Analysis of variance on: Arcsine transformed V frequency developed ovules.

Anova Source of variation df SS MS F Among groups 5 267.96 53:59 E52 Not significant Within groups 12. 422.89 35.24 Total 17. =—690.85 Groups 1+ 3vs.2+4+4+5+4+ 6 1 0.639 0.639 0.018 Not significant

TABLE 3. RELATION BETWEEN OCCURRENCE OF INDIVIDUALS IN THE CLUSTER DEFINED BY THE 3RD PRINCIPAL COORDINATE ANALYSIS AXIS AND HABITAT TYPE.

Principal Habitat coordinate axis III Grassland Oak forest Chaparral Total + Cluster 15 3 31 49 — Cluster 93 51 39 183 Total 108 54 70 Zon

x” = 33.8 df = 2; p < 0.001; G.E.T. p = 5.7 X 10°8.

TABLE 4. RELATION BETWEEN OCCURRENCE OF INDIVIDUALS OF ELECTROPHO- RESIS LEUCINE AMINOPEPTIDASE PHENOTYPES AND HABITAT TYPE.

LAP phenotype

Habitat Fast band only Fast and slow bands Total Oak forest 11 | 38 Grassland 35 114 149 Chaparral 46 54 100 Total 92 195 287

x? = 14.1 df = 2; p < 0.001; G.E.T. p = 0.000757.

28 MADRONO [Vol. 30

pothesis must be rejected (G.E.T. p = 5.7-10°8; x? = 33.8, df = 2, p < 0.001) based on the data of Table 3. Thus, it appears that habitat type is associated with phenotype.

Individual genetic traits were examined by isozyme analysis in 287 offspring rosettes via slab acrylamide gel electrophoresis. The malate dehydrogenase, lactate dehydrogenase, and “general protein” stains were monomorphic and will not be discussed further.

The leucine aminopeptidase (LAP) results are presented in Table 4, which relates the results to habitat type. The differences are denoted slow and fast, where slow bands remained closer to the origin than the fast bands. LAP electrophoretic phenotypes all contained the fast band, but some contained a slow band while others did not. Both the chi-square and generalized exact test were performed (G.E.T. p = 0.000757; yx? = 14.1, df = 2, p < 0.001). Thus, LAP genotype distri- bution was correlated to habitat type, which suggests that morphs correlated to habitat may also have a genetically based component. The alkaline phosphatase and acid phosphatase data are published elsewhere (Wells and King 1980). The alkaline phosphatase genotypes resembled those of LAP in being correlated with habitat type (G.E.T. p = 0.023) whereas those of acid phosphatase were uniformly distrib- uted (G.E.T. p = 0.412).

The correlation between habitat and both morphological and elec- trophoretic phenotypes presents an additional question. Is micro-hab- itat selection actually occurring, rather than an elevationally related cline, or even selection by some environmental factor(s) not determin- ing habitat?

Hypotheses generated by these questions can be tested because of the population structure of Czrstum in Happy Canyon, 1.e., the spatial and elevational isolation of grassland region 3 from 1 & 2. Morpho- logically, 9.1% of the Cirsium of grassland No. 3 are from the + cluster (n = 11), in comparison to 14.4% of grassland Cirsium 1 & 2 (n = 97). LAP electrophoretic data had 13.0% of grassland region 3 Cirsium with only the fast band (n = 23), while 25.4% of area No. 1 & 2 Cirsium had only the fast band (n = -126).

If a cline or a nonhabitat-related environmental factor were oper- ative, then, grassland Czrszum colonies 1 & 2 should differ from No. 3, and both grassland Cirstum No. 3 and No. 1 & 2 should differ from the intervening chaparral Cirsium. However, if habitat-related selec- tion is occurring then one would expect Cirsium in grassland habitats 1 & 2 and 3 not to be significantly different, but that they would differ from those Cirsium found in the chaparral.

Grassland Cirsium in regions 1 & 2, as defined morphologically by the principal coordinate analysis, did not differ significantly from those in region 3 (G.E.T. p = 0.72, x? = 0.21, df = 1, p > 0.6), but each did differ significantly from the chaparral Cirsium (grassland 1 & 2 vs. chaparral: G.E.T. p = 2.19 x 10-5; y? = 18.29, df = 1; p<

1983] WELLS: HYBRIDIZATION IN CIRSIUM 29

0.005; grassland 3 vs. chaparral: G.E.T. p = 0.0431; x? = 4.93, df = 1, p < 0.05). The LAP isozyme data showed the same pattern of differences as morphology (grassland 1 & 2 vs. 3: x? = 1.65, df = 1, p > 0.2; grassland 1 & 2 vs. chaparral: y? = 10.50, df = 1, p < 0.005; grassland 3 vs. chaparral: y? = 8.47, df = 1, p < 0.005). Alkaline phosphatase data (Wells and King 1980), however, showed significant differences only between grassland 1 & 2 and chaparral Cirsium (G.E.T. p = 0.0265), but not between the grassland 1 & 2 and 3 Cirstum (G.E.T. p = 0.84), or between grassland 3 and chaparral Cirsium (G.E.T. p = 0.0682).

CONCLUSIONS

1. The Happy Canyon Cirsium population consists of one biological species with no sterility barriers.

2. Morphological and electrophoretic phenotypes correlated with hab- itat type appear to have a genetic basis.

3. The differentiation corresponding to habitat types suggests that several phenotypic traits may be subject to selection and that dif- ferentiation along new lines may have resulted after hybridization of C. californicum and C. occidentale in the Happy Canyon pop- ulation.

ACKNOWLEDGMENTS

I thank Dr. D. M. Smith, Dr. J. L. King, Dr. A. Wenner, and Dr. P. H. Wells for reviewing earlier versions of this manuscript. Very useful suggestions for improving the article were also supplied in the review process by J. Strother, C. Davidson, and an unknown reviewer.

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populations in biennial species? A study using Verbascum virgatum (Scrophular-

iaceae). Genet. Res. Cambridge 36:17—28.

A NEW GYPSOPHILIC SPECIES OF GALIUM (RUBIACEAE) FROM NORTH-CENTRAL MEXICO

B. L. TURNER and GAYLE TURNER Department of Botany, The University of Texas, Austin 78712

ABSTRACT

A new species, Galium dempsterae, is described from gypseous deposits in north- central Mexico. It is known from only two collections, both obtained from Cerro Pena in southern Nuevo Leon. The taxon is related to yet another gypsophile, G. juniper- inum, from areas about Cerro Potosi, Nuevo Leon; both of these taxa relate to G. lacrimiforme, a suspected gypsophile of the same broad region.

Explorations, both past and recent, of the numerous and often lo- cally large gypseous outcrops in north-central Mexico have yielded a number of interesting endemics, some of them quite bizarre (Turner 1973, Turner and Powell 1979, Higgins and Turner 1982). Detection of the species of Galium described below is surprising because the genus recently received a thorough taxonomic treatment by Dempster (1977).

Galium dempsterae B. L. Turner, sp. nov.

G. juniperino Standley simulans sed foliis nonadpressis glabris, pe- dicellis longioribus, pilis fructuum brevibus valde incuratis (Fig. 1).

Polygamous suffrutescent rhizomatous coarse perennials, 10-12 cm tall; stems costate, divaricately branched, glabrous except for a circle of hairs ca. 0.1 mm long below each node; leaves in 4’s, longer than the nodes except in inflorescence, glabrous, (2.5—)3—4(—5.2) mm long, 0.7-1.0 mm wide, subulate, pungent, spreading, thickish, faintly 1-nerved, sessile; glandular cells absent; inflorescence strict, the flow- ers in axillary 3(—5)-flowered dichasia in the upper leaf axils; peduncles 1.0-4.2 mm long, leafy bracts 2, 2-4 mm long, pedicels 1.7—4.0 mm long; corollas rotate, glabrous, yellowish-green, 2.0—-3.3 mm wide, lobes 4, ovate, apices acute to acuminate; filaments 0.2—0.3 mm long; an- thers yellow, 0.2—0.3 mm long; style 0.6—0.7 mm long (wet), divided ca. halfway to base; fruits dry (immature), set with very short, up- wardly directed strongly incurved hairs, 0.1—0.2 mm long.

TYPE: Mexico, Nuevo Leon; gypsum outcrops on nw. slope of Cerro Pena Nevada, ca. 7 km ne. of San Antonio Pena Nevada (ca. 30 km nw. of Doctor Arroyo), Jul 1977, C. Wells & G. Nesom 514 (Holotype EL:

MADRONO, Vol. 30, No. 1, pp. 31-33, 28 January 1983

32 MADRONO [Vol. 30

Sem

Fic. 1. Habit sketch of Galium dempsterae (x1). Inserts: a, fruit (10); b, node, showing hairs (6).

PARATYPE: Nuevo Leon: ca. 30 km ene. of San Antonio de Pena Nevada, base of Cerro Pena Nevada, “large area of gypsum outcrops,” 6600 ft, 3-5 Aug 1981, G. Nesom 4262 (TEX).

The species is apparently most closely related to yet another gyp- sophile, Galium juniperinum Standl., which occurs as a local domi- nant on the largely barren white gypseous soils about the village of Galeana some 120 km due north of the present site. Dempster (1977) in her critical, delightful, treatment of Galiuwm for Mexico and Central America notes only a single collection (the type) of G. juniperinum. We have noted the species several times on gypseous outcrops near Galeana and have collected it on gypsum substrates on the north- eastern lower slopes of Cerro Potosi, ca. 7.5 km northwest of Galeana (Turner & Davies A-10, TEX).

The fruit of Galium dempsterae is presumably similar to what we

1983] TURNER AND TURNER: NEW GALIUM 33

suspect is yet another gypseous endemic, G. lacrimiforme Dempster, known only from a single collection, ca. 13 km east of Dulces Nombres, Nuevo Leon, a region where gypseous outcrops are known to occur. Additional new taxa are likely to be found upon the various isolated, largely unexplored, gypseous outcroppings in north-central Mexico (Turner and Powell 1979).

It is a pleasure to name this species for Lauramay T. Dempster, whose very sound treatment of this difficult genus made easy our assessment of the present contribution. We are grateful to Dr. M. C. Johnston for providing the Latin diagnosis and to Dr. J. Henrickson for helpful suggestions.

LITERATURE CITED

DEMPSTER, L. T. 1977. The genus Galium (Rubiaceae) in Mexico and Central Amer- ica. Univ. Calif. Publ. Bot. 73:1-33.

HIGGINS, L. and B. L. TURNER. 1983. Antiphytum hintoniorum (Boraginaceae), a bizarre new gypsophile from north-central Mexico. Southwestern Natur. (In press).

TURNER, B. L. 1973. Machaeranthera restiformis (Asteraceae) a bizarre new gypso- phile from north-central Mexico. Amer. J. Bot. 60:836-838.

and A. M. POWELL. 1979. Deserts, gypsum and endemism. in J. R. Goodin

and D. K. Northington, eds., Arid land resources. Texas Tech Univ., Lubbock.

PIONOCARPUS BECOMES IOSTEPHANE (COMPOSITAE: HELIANTHEAE): A SYNOPSIS

JOHN L. STROTHER Botany, University of California, Berkeley 94720

ABSTRACT

Iostephane comprises four Mexican species, including Iostephane madrensis (S. Wats.) Strother (=Helianthella madrensis, the type of Pionocarpus S. F. Blake). The species are clearly allied with members of Heliantheae but without an obvious nearest relative.

Perpetuation of Pzonocarpus (a pappose monotype) is no longer ten- able, in view of overall agreement in habitat preference, habit, and details of vegetative and floral morphology among members of Jos- tephane (originally characterized as epappose) and P. madrensis, which is here transferred to Jostephane. Indeed, some plants of /. madrensis from Durango and Zacatecas very closely approach, in vegetative and floral detail, plants of J. papposa from Oaxaca. One robust specimen from Durango (see discussion of J. madrensis) may be a hybrid be- tween I. madrensis and I. heterophylla. Rather than make a bald transfer, I append a taxonomic synopsis of the now four species of Tostephane.

Members of lostephane are all subscapiform, heavy-rooted peren- nials that inhabit pine, oak, or pine-oak forests between 1500 and 3000 m in Mexico, ranging from Sinaloa, Chihuahua, and Durango east and south to western Veracruz and central Chiapas. With regard to floral characteristics, the plants are clearly allied with members of Helianthinae s.str., near to but isolated from plants now assigned to Viguiera H.B.K. s.l.

IOSTEPHANE Benth. in Benth. & Hook., Gen. Pl. 2:368. 1873.—TYPE: IOSTEPHANE HETEROPHYLLA (Cav.) Benth. ex Hemsl. = Cor- eopsis heterophylla Cav.

Pionocarpus S. F. Blake, Proc. Amer. Acad. Arts 51:521. 1916.— TYPE: Pionocarpus madrensis (S. Wats.) S. F. Blake = Helian- thella madrensis S. Wats. = IOSTEPHANE MADRENSIS (S. Wats.) Strother.

Scapiform perennial herbs to 15 dm high, rhizomatous from tu- beriform rootstocks; leaves mostly in basal rosettes, very variable among plants, less so within plants, petioles winged, at least distally, blades membranous to coriaceous, lanceolate to broadly ovate or deltoid,

MADRONO, Vol. 30, No. 1, pp. 34-38, 28 January 1983

1983] STROTHER: SYNOPSIS OF IOSTEPHANE 39

often with a deep, rounded sinus on each side, thus pandurate to 3-lobed, cuneate to subtruncate or subcordate basally, obtuse to acute or acuminate apically, entire to subentire to coarsely dentate with callous teeth, coarsely scabrous to nearly glabrous; heads solitary or 2—5(—12) in very loose associations; peduncles scapiform, bracteate, often swollen and fistulose distally; involucres turbinate to hemispher- ic, 1-2 cm high; phyllaries 12—26 in 2(—3) series, herbaceous, subequal, lance-linear to broadly lanceolate or lance-ovate, acute to acuminate, strigo-pilose; paleae scario-cartilaginous, navicular, keeled or not, acu- minate, pungent, closely strigose; receptacles convex to conical; ray florets 8-21, neutral or styliferous but infertile, corollas purplish to pink (sometimes white) or yellow to orange, tube stout, lamina oblong to ovate, showy; disc florets 15-110+, perfect, corollas yellow (some- times with purplish lobes), tube usually glabrous, length <% that of the abruptly ampliate, cylindric, sparsely pubescent to densely hispid- ulous throat, lobes 5, equal, narrowly deltoid, abaxially pubescent; anthers blackish, very slender, minutely sagittate; style branches rath- er stout, abruptly hispidulo-penicillate; achenes purplish black, slight- ly laterally compressed, oblong-obovate in profile, typically quadrate in cross-section, glabrous to strigose; pappus none or of 0-2 fragile or deciduous, setose squamellae 1-3 mm long plus O—4(—18) erose-lacer- ate, free or connate squamellae 0.5—1 mm long; chromosome number, x= 17,

Key to species of lostephane

Phyllaries mostly lanceolate to lance-ovate, (3—)4—7 mm wide; ray co- rollas purple to pink (rarely white), lamina 25-58 mm long .... Pee MR asthe. Shite Sse ntatne tech aoa fe resea cr aecir ose e. & I. heterophylla

Phyllaries mostly linear to lance-linear, 1.5—3(—4) mm wide; ray co- rollas yellow to orange, lamina 9-31 mm long.

Ray florets mostly 5—9; disc florets mostly 15—40, corollas 5(4.2—6) mm long; achenes mostly 3.5—4.5 mm long, glabrous; epappose arch eer eee tala areata. ctemen nese Panes eesee netant I. trilobata

Ray florets mostly 13(8—16); disc florets mostly 35-60, corollas 6(5.5— 8.5) mm long; achenes mostly 4.5—5.5 mm long, sparsely to prominently strigose; pappus of setose and/or erose-lacerate scales.

Leaf blades typically linear to narrowly lanceolate, length mostly 5—8+ times width, none lobed; pappus of 0-2 setae plus 10— 18 erose scales; nw. Mexico ............... I. madrensis Leaf blades typically ovate to deltoid to broadly lanceolate, length mostly 1—3 times width, often some or all lyrate to pandurate; pappus of O—2 setae plus 2—4 erose scales; se. Mexico .....

I a gat So tea aan Bencaed ns San Pie it ag ea EE I. papposa

36 MADRONO [Vol. 30

IOSTEPHANE HETEROPHYLLA (Cav.) Benth. ex Hemsl., Biol. Cen. Amer. Bot. 2:168. 1881.—Coreopsis heterophylla Cav., Icon. Pl. 3:34, pl. 268. 1795.—Simsia heterophylla (Cav.) Pers., Synop. Pl. 2:478. 1807.—Ximenesia cavanillesii Spreng., Syst. Veg., 16th ed. 3:605. 1826, nom. nov.—Echinacea heterophylla (Cav.) D. Don in Sweet, Brit. Fl. Gard. ser. 2. 1: pl. 32. 1831 [1830].— Type: Grown in Madrid from Mexican seed; the plate fixes ap- plication of the name.

Rudbeckia napifolia H.B.K., Nov. Gen. Sp. 4:244. 1820.—TyYPE: “Crescit juxta Santa Rosa de la Sierra, alt. 1300 hex (Nova His- pania). 2+ Floret Septembri,” Humboldt and Bonpland s.n. (Ho- lotype: P, microfiche!).

Echinacea dicksoni Lindl., Edward’s Bot. Reg. 24: pl. 27. 1838.— Tostephane heterophylla (Cav.) Benth. ex Hemsl. var. dicksonii (Lindl.) W. M. Sharp, Ann. Missouri Bot. Gard. 22:82. 1935.— TYPE: Grown in England by the Horticultural Society from Mex- ican seed; the plate fixes application of the name.

Echinacea dubia Knowl. & Westc., Fl. Cab. 3:163, pl. 131. 1839.— TYPE: Grown by Birmingham Botanical and Horticultural Soci- ety from Mexican seed; the plate fixes application of the name.

Tostephane heterophylla (Cav.) Benth. ex Hemsl. var. acutiloba W. M. Sharp, Ann. Missouri Bot. Gard. 22:83. 1935.—TYPE: Mex- ico, Jalisco, near Guadalajara, Aug 1893, C. G. Pringle 4480 (Holotype: MO!; isotypes: F!, GH!, MIN!, MO!, MSC!, NY!, UC!, US!).

Plants 3—9(—15) dm high; petioles 4—12(2—25) cm long, leaf blades 6— 15(3-27) cm long, 5—12(2—18) cm wide; phyllaries 14-26, lance-ovate to lanceolate, 16(8—28) mm long, 3—7 mm wide; paleae 8.4—-11.8 mm long; ray florets 8-21, corollas typically purple to magenta or pinkish, exceptionally white (e.g., Guerrero, Moore 4534, A, MICH), lamina 25-58 mm long; disc florets 50-100+, corollas 6.2—9.1 mm long; achenes 3.6—6.6 mm long, sparsely to moderately strigillose; pappus none or of 1—2 setose squamellae 1-2 mm long plus 0-4+ cuneate to lanceolate, erose to lacerate scales less than 1 mm long (e.g., Puebla, Aug 1908, Purpus s.n., UC); chromosome number, 2” = 34.

Known mostly from pine, oak, and pine-oak forests or adjacent clearings or meadows, sometimes drier forest with junipers, 1500—3000 m, in Mexican states: Chih., Sin., Dgo., S.L.P., Gto., Aguasc., Jal., Mich., Mex., D.F., Hgo., Pue., Mlos., Gro., Ver., and Oax.

Iostephane madrensis (S. Wats.) Strother, comb. nov.—Helianthella madrensis S. Wats., Proc. Amer. Acad. Art 23:278. 1888.—Pziono- carpus madrensis (S. Wats.) S. F. Blake, Proc. Amer. Acad. Arts 51:522. 1916.—TYPE: Mexico, Chihuahua, “pine plains at the base of the Sierra Madre,” Sep 1887, C. G. Pringle 1302 (Holo- type: GH!; isotypes: F!, NY-2!, US!).

1983] STROTHER: SYNOPSIS OF IOSTEPHANE 37

Helianthella iostephanoides Greenm., Proc. Amer. Acad. Arts 40:41. 1904.—TyYPE: Mexico, Zacatecas, “in the Sierra Madre,” 18 Aug 1897, J. N. Rose 2391 (Holotype: GH!; isotype: US!).

Plants mostly 3—7 dm high; petioles 6—12 cm long, leaf blades linear to lanceolate, 10—16(—25) cm long, 1—3(—6) cm wide; paleae 9-11 mm long; ray florets 9-16, corollas yellow, lamina 9—15(—30) mm long; disc florets 35-60, corollas 5.5—6 mm long; achenes 5—5.5 mm long, strig- illose; pappus of 0-2 setose squamellae 2-3 mm long plus, typically, 10-18 free or connate, erose-lacerate scales 0.3—1 mm long; chromo- some number unknown.

Known from pine and pine-oak forests between 2100 and 2650 m in Chih., Dgo., Gto., Jal., and Zac. Breedlove 44199 (CAS) from 65— 75 km sw. of Cd. Durango is exceptional in having leaf blades roughly 10-15 cm long by 4-6 cm wide and ray florets with laminas to 3 cm long. I first took the plant to be a yellow-rayed form of J. heterophylla. Now I think it may be a hybrid involving that taxon and /. madrensis. Pollen from the specimen appears to be normal and fertile (stained in lactophenol cotton-blue).

IOSTEPHANE PAPPOSA Fay, Brittonia 25:192. 1973.—TYPE: Mexico, Oaxaca, ca. 10 km s. of Suchix[s]tepec (ca. 95 km n. of Puerto Angel), 2300 m, 8 Nov 1970, A. Cronquist 10895 (Holotype: NY}; isotypes: ENCB!, MEXU, MICH!, UC!, UTC).

Plants 4-6 dm high; petioles 4—12(3—15) cm long, leaf blades 6-12 (—-15) cm long, 3—6(—8) cm wide; phyllaries 18-22, lance-linear to lin- ear, 8-15 mm long, 1.6—2.8 mm wide; paleae 8—-10.5 mm long; ray florets 8-13, corollas yellow to orange, lamina 17-31 mm long; disc florets 30-50, corollas 5.9-8.5 mm long; achenes 4.2—4.5 mm long, sparsely strigillose; pappus of (1—)2 setose squamellae 1.5—3 mm long plus 2—6 cuneate to lanceolate, erose-lacerate scales ca. 0.5 mm long; chromosome number unknown.

Known only from six gatherings made in pine-oak forests in Oaxaca at 2200-2700 m: five from ca. 100 km s. of Oaxaca along route 175 from Oaxaca to Puerto Angel (vicinity of type locality) and one from 2 km e. of Ixtan de Juarez, ca. 30 km ne. of Oaxaca (Hill 1803, NY).

IOSTEPHANE TRILOBATA Hemsl., Biol. Cen. Amer. Bot. 2:169. 1881.— TYPE: Mexico, Chiapas, without locality or date, Ghiesbreght 101 (Holotype: K; isotype: GH!).

Rudbeckia chrysantha Klatt, Leopoldina 23:143. 1887.—[Echinacea chrysantha Sch.-Bip., in sched. fide Klatt, loc. cit. |—TyPE: Mex- ico, “Cumbre de Estepa,” Liebmann “575” (Holotype: C; leaf and drawing: GH!).

Gymnolomia scaposa Brandegee, Univ. Calif. Publ. Bot. 4:93. 1910.— TYPE: Mexico, Puebla, near Coaxcatlan, oak forests, 83000—9000

38 MADRONO [Vol. 30

ft, Sep 1909, C. A. Purpus 4120 (Holotype: UC!; isotypes: F!, GH!, MO!, NY!, US!).

Plants 2-6 dm high; petioles 6—10(3—15) cm long, leaf blades 6—8(3-— 12) cm long, 3—4(2—6) cm wide; phyllaries 12—21, lance-linear to linear, 6-12 mm long, 1.5—3.1 mm wide; paleae 5.8—9.8 mm long; ray florets 5—9, corollas yellow to orange, lamina 9—20 mm long; disc florets 15— 40, corollas 4.2—6 mm long; achenes 3.2—4.8 mm long, glabrous; pap- pus none; chromosome number, 2” = 34, ca. 68.

Known from pine-oak forests between 1500 and 2600 m, principally in Chiapas and Oaxaca; other collections: Mexico, Cumbre de Estepa, Liebmann 575 (GH); Mexico, near Nanchitla (ca. 80 km wsw. of Mex- ico City), 7 Oct 1933, Hinton 4965 (GH, MO, NY, US); same locality, 15—16 Sep 1958, Matuda 32806 (CAS, ENCB); Mexico, Cerro de Jilo- tepec (ca. 65 km nnw. of Mexico City), 27 Sep 1953, Matuda 29094 (NY); Puebla, Coaxcatlan (se. of Tehuacan, ca. 18°16’N, 97°09’W), Sep 1909, Purpus 4120 (F, GH, MO, NY, UC, US). Specimens of this species labeled as coming from Durango VJ/ackson 7190 in UC and 7191 in NY) are actually from Oaxaca (Jackson, pers. comm.).

ACKNOWLEDGMENTS

I thank staff of CAS, COLO, DS, ENCB, F, GH, LL, MICH, MIN, MO, MSC, NY, POM, RSA, TEX, US, and WIS for loans of specimens.

CERATOZAMIA MICROSTROBILA (ZAMIACEAE), A NEW SPECIES FROM SAN LUIS POTOSI, MEXICO

ANDREW P. VOVIDES Instituto Nacional de Investigaciones sobre Recursos Bioticos, Xalapa, Veracruz, Mexico

JOHN D. REES Department of Geography and Urban Studies, California State University, Los Angeles 90032

ABSTRACT

Ceratozamia microstrobila is described from southeastern San Luis Potosi, Mexico. It is compared with C. zaragozae Medellin-Leal and C. hildae Landry & Wilson, to which it is mostly closely related.

We believe the genus Ceratozamia is highly variable, and the pos- sibility of natural hybrids exists. We have found differences within and between populations of the same species in leaflet width and length, as well as in mature cone sizes. However, we feel the genus seems to form two main groups: large plants with large trunks, many leaves, and large cones, of which C. mexicana Brogn. is typical; and a group of small plants with small, almost subterranean trunks, bearing few small leaves and small cones, to which belong C. zaragozae Medellin- Leal, C. hildae Landry & Wilson, and the species described below.

Ceratozamia microstrobila, Vovides & Rees, sp. nov.

Truncus ovoideus vel subcylindricus, usque ad 24 cm longus et usque ad 10 cm diametro; folia pinnata usque ad 70 cm longa; petiolus inermis, basi tomentosus; cataphylla triangula, tomentosa, cauli ad- nata, 3-5 mm longa; foliola lanceolata, 15-18 cm longa, 2.8—3.2 cm lata, ad marginem subrevoluta, apice acuta, strobilus masculinus, 17 cm longus, 2.3 cm diametro, brunneus, pedunculatus; pedunculus iner- mis, tomentosus, 5 cm longus; microsporophylla bicornia, 7 mm longa, 5 mm lata, cornua 2 mm longa, parte sterili inter cornua 2 mm longa; strobilus femineus pedunculatus, subcylindricus, viridi-brunneus, 6 cm longus, 4.4 cm diametro; megasporophylla peltata, 1.7-2.1 cm lata, 1.2-1.3 cm longa, bicornia, cornua 2 mm longa; pedunculus inermis, tomentosus, 6 cm longus (Fig. 1).

Trunk almost subterranean, ovoid to subcylindric, up to 24 cm long, 10 cm maximum diameter, protected by the persistent leaf bases, light brown in color. Leaves 2—4, pinnate, up to 70 cm long, unarmed;

MADRONO, Vol. 30, No. 1, pp. 39-42, 28 January 1983

40 MADRONO [Vol. 30

it py

ud

FIG. 1. Ceratozamia microstrobila Vovides & Rees. A. Habit of female plant. B. Female cone. C. Megasporophyll with attached seeds. D. Male cone. E. Microsporo- phyll. F. Cataphyll. G. Seed with emerged radicle and taproot.

petiole tomentose at base. Cataphylls triangular, tomentose, 3-5 mm long. Leaflets lanceolate 15-18 cm long, 2.8—3.2 cm wide, alternate, subopposite or opposite, acute at apex, coriaceous, entire, subrevolute, lustrous green on adaxial surface, lighter green on abaxial surface;

1983] VOVIDES AND REES: NEW CERATOZAMIA 41

nerves more or less visible. Male cone 17 cm long, 2.3 cm diameter, brown; peduncle 5 cm long, unarmed, tomentose; microsporophylls (from median part of cone) 5 mm wide, 7 mm long, horns 2 mm long, 4.5 mm apart, length of infertile portion between the horns 2 mm. Female cone greenish brown, 4.4 cm in diameter, 6 cm long; peduncle 6 cm long, unarmed, tomentose; cataphyll triangular, 4 mm long, heavily tomentose; megasporophylls peltate, 1.7—2.1 cm wide, 1.2—1.3 cm long, pubescent at edges, horns 2 mm long, spaced 1.4 cm apart; seeds slighty elongate, 1.4 cm in diameter, 1.8—1.9 cm long. 2n = 16.

TYPE: Mexico, San Luis Potosi, Municipio of Ciudad del Maiz, at Ejido las Abritas, 850 m, 3d, 7 Nov 1974, J. Rees 1613 (Holotype: XAL).

PARATYPE: Mexico, San Luis Potosi, Municipio of Ciudad del Maiz, at Ejido las Abritas, 24 Sep 1977, J. Rees 1681 (MEXU).

The new taxon is known only from Ejido las Abritas at 850 m. It grows in shallow reddish clay soil, rich in humus, on limestone out- crops. The site is located in the transition zone between low deciduous forest (selva baja caducifolia) and mixed oak woodland. Genera pres- ent at the site include: Quercus spp., Ostrya sp., Ulmus sp., Dendro- panax sp., Cupania sp., Sabal sp., Bursera [aff. stmaruba (L.) Sarg. ], and Hamelia sp. Also present are two other cycads: Dioon edule Lind- ley and Zamza fischeri Miq.

Vegetative key

Leaflets fasciculate. Leaflets 1 to 3 cm wide, arranged in clusters of 2 to 4 along rachis, up to 11 pairs of clusters .................... 1. C. hildae Leaflets not fasciculate. Leaves irregularly twisted; leaflets linear lanceolate, not exceeding 1 cm in width, up to 19 pairs ............ 2. C. zaragozae Leaves not irregularly twisted; rachis unarmed; leaflets lanceolate, 15 to 18 cm long, 2.8 to 3.2 cm wide, up to 16 pairs ....... Bete Re a ee ee ee arg 3. C. microstrobila

These three small Ceratozamia species from eastern Mexico form separate populations and are morphologically distinct from each other. Ceratozamia microstrobila is distinguished from C. hildae Landry & Wilson by having lanceolate, not fasciculate, leaflets, and from C. zaragozae Medellin-Leal by not having irregularly twisted leaflets. The chromosome numbers and karyotypes of the three small species are similar to those of C. mexicana, as published by Marchant (1968); however, each of the species differs in the number of satellites present (Vovides, unpubl. data).

Additional field collections are needed of the small Ceratozamia species from eastern Mexico. They have been collected at only a few sites, where they are being removed rapidly by commercial collectors.

42 MADRONO [Vol. 30

Their ranges, variation, and cytology have not been adequately stud- ied. The morphology and cytology of these plants and their relation- ships to the larger Ceratozamia species are now undergoing study by authors.

ACKNOWLEDGMENTS

We wish to thank Sra. Elvia Esparza A. of INIREB for the excellent botanical illustrations produced for this publication, and Mr. E. Johnson for revising the Latin.

LITERATURE CITED

LANDRY, G. P. and M. C. WILSON. 1979. A new species Ceratozamia (Cycadaceae) from San Luis Potosi. Brittonia 31:422—424.

MARCHANT, C. J. 1968. Chromosome patterns and nuclear phenomena in the cycad families Stangeriaceae and Zamiaceae. Chromosoma 24:100-134.

MEDELLIN-LEAL, F. 1963. A new species of Ceratozamia from San Luis Potosi. Brittonia 15:175—-176.

VovIDES, A. and J. REES. 1980. Datos adicionales sobre Ceratozamia hildae Landry et Wilson 1979 (Zamiaceae). Biotica 5(1):1—4.

COMPETITION FOR LIGHT AND A DYNAMIC BOUNDARY BETWEEN CHAPARRAL AND COASTAL SAGE SCRUB

JOHN T. GRAY Dames & Moore, Environmental and Earth Sciences, 222 E. Anapamu St., Santa Barbara, CA 93101

ABSTRACT

A sharp boundary between mature stands of Ceanothus chaparral and coastal sage scrub was found in the Santa Monica Mountains in coastal southern California. The presence of numerous dead coastal sage scrub species in the understory of the chaparral suggests that the chaparral has been progressively invading the coastal sage scrub during the last several fire cycles.

McPherson and Muller (1967) demonstrated that light competition occurred between the chaparral shrub, Ceanothus cuneatus, and the drought-deciduous shrub, Salvia leucophylla, at an inland site in southern California. Seedlings of both species apparently established together following a fire; however, after 26 years, the evergreen shrubs had overtopped and suppressed the drought-deciduous shrubs. Using both field and lab experiments, McPherson and Muller (1967) elimi- nated the role of phytotoxins, soil moisture, and soil nutrients in cre- ating the observed pattern. They showed that the taller Ceanothus shrubs interfered sufficiently with light reaching shorter Salvia shrubs to eliminate them after 26 years.

In this paper, I report a similar case of apparent light competition between the chaparral shrub, Ceanothus megacarpus, and several drought-deciduous shrub species at a coastal site in southern Califor- nia. I also hypothesize about the long-term dynamics of the chaparral/ coastal sage scrub ecotone at this site.

At mid-elevations (100-300 m) along the immediate coast of the Santa Monica Mountains 50 km northwest of Los Angeles, mature stands of chaparral and coastal sage scrub occur together and often form a mosaic across the landscape. The chaparral is dominated by Adenostoma fasciculatum or Ceanothus megacarpus (Bauer 1936), whereas the coastal sage scrub is comprised of the common drought- deciduous shrubs Artemisia californica, Salvia leucophylla, and S. mellifera (Kirkpatrick and Hutchinson 1977, Gray and Schlesinger 1981, Westman 1981). Where the two vegetation types meet, there often is a sharp boundary between them, even in the absence of ob- vious edaphic or geologic discontinuities. This pattern suggests that biotic interactions, historic factors (fire, grazing, human activity), or both, may be important.

MADRONO, Vol. 30, No. 1, pp. 43-49, 28 January 1983

44 MADRONO [Vol. 30

Fic. 1. Adjacent, even-aged stands of Ceanothus chaparral (dark region, left fore- ground) and coastal sage scrub (light regions) in the Santa Monica Mountains of southern California. Mixed Adenostoma chaparral is in the upper left. There is a road cut in the foreground.

METHODS

Adjacent, mature stands of chaparral and coastal sage scrub, lo- cated in the Santa Monica Mountains (150 m elevation and 3 km from the ocean), were the site of a three-year comparative study of produc- tivity and nutrient cycling (Gray 1982, 1983) and are shown in Fig. 1. Wildfire burned through the canyon and study site in 1956 according to local residents and California Department of Park and Recreation officials.

To determine canopy cover and density of individual species in the chaparral and coastal sage scrub, 50-m sample transects were con- ducted through the center of each community. One-hundred paired, 1 X 1-m quadrats were sampled along each transect line. The presence of all live and dead individuals of all shrub species in each quadrat was recorded. Canopy cover was estimated by measuring the canopy projection of each species along a 50-m tape (line intercept method). Relative cover was calculated for each species as the total distance covered by the canopy of a species divided by the total distance cov- ered by the canopies of all species.

Dead shrubs of all species were remarkably intact, particularly in the chaparral: all were rooted, relatively unweathered, and undis- turbed by animal activity. Each dead shrub was identified to species

1983] GRAY: COMPETITION IN COASTAL SAGE SCRUB 45

by using species characteristics of branching geometry (Salvia leuco- phylla, Eriogonum parvifolium), stem morphology (Ceanothus mega- carpus), and bark texture (Artemisia californica, Adenostoma fasci- culatum, Eriophyllum confertiflorum).

Eighteen whole shrubs of Ceanothus megacarpus were harvested in June 1979 using a stratified-random selection (Gray 1982). The age of each shrub was determined by ring counts at the base of the stems.

RESULTS AND DISCUSSION

The chaparral stand was completely dominated by Ceanothus megacarpus in terms of cover and density (Table 1). Living Ceanothus megacarpus shrubs were 4—6 m in height and the foliage was concen- trated in the upper 75 cm. The canopy was completely closed. Nu- merous, attached dead branches were present in the lower portions of the shrubs, a characteristic of other Ceanothus species in the chaparral (Keeley 1975).

The age of the living Ceanothus shrubs ranged from 20-22 years in the sample shrubs. Ceanothus megacarpus does not crown sprout and reproduces only by seed after a fire. It typically forms rapidly growing stands of even-aged individuals (Schlesinger and Gill 1980).

Several other species were present in the chaparral, but were few in number (Table 1) and 1—-1.5 m shorter than Ceanothus megacarpus. Several of these species, including Eriogonum, Cercocarpus, and Ad- enostoma exhibited broad, etiolated leaves typical of shade plants (Boardman 1977), appeared to be growing slowly, and did not flower during the three years of the study.

Numerous standing dead individuals of both evergreen and drought- deciduous species were also in the understory of the chaparral (Table 1). The dead Ceanothus megacarpus shrubs were 10—12 years old and small in stature. These plants appeared to be aggregated, as suggested by the high standard deviation associated with their density values (Table 1). These dead individuals of Ceanothus were apparently elim- inated by intra-specific competition for water during early stand de- velopment as shown by Schlesinger and Gill (1980).

The drought-deciduous species in the understory of the chaparral were the same species that comprised the adjacent coastal sage scrub (Tables 1, 2). All individuals of coastal sage scrub species in the chap- arral were dead with the exception of Evriogonum and Yucca. In con- trast, mortality in the coastal sage scrub community was only a small percentage of the total number of shrubs and was restricted to Arte- mista and Salvia (Table 2). The density of dead Artemisia and Salvia shrubs in the chaparral was significantly less than for live shrubs in the coastal sage scrub. Only 10% of the dead Artemisia and Salvia shrubs in the chaparral appeared to have arisen from crown sprouts, compared to 33% of the live shrubs in the coastal sage scrub.

46 MADRONO [Vol. 30

TABLE 1. PERCENT RELATIVE COVER AND ABSOLUTE DENSITY OF INDIVIDUALS IN THE Ceanothus CHAPARRAL. Standard deviations (S.D.) are given for the density values, n = 100.

Evergreen (FE) or Density drought- (individuals deciduous’ Relative per square Species (DD) leaves cover (%) meter) S.D. Live plants Ceanothus megacarpus E 99 2.67 2.68 Adenostoma fasciculatum E 1 0.13 0.43 Eriogonum parvifolium DD 1 0.09 0.24 Yucca whipplei E 1 0.07 0.24 Ceanothus spinosus E 1 0.03 0.23 Cercocarpus betuloides E if 0.02 0.08 Rhus laurina E 1 0.01 0.07 Dead plants Ceanothus megacarpus E — 1 BS: Sid Adenostoma fasciculatum E — 0.30 0.38 Eriophyllum confertiflorum DD — 0.30 0.47 Eriogonum parvifolium DD — 0.25 0.43 Artemisia californica DD i 0.18 0.42 Salvia leucophylla DD = 0.10 0.20 Yucca whipplei E — 0.01 0.07 Ceanothus spinosus E — 0.01 0.07

The presence of dead coastal sage scrub species in the understory of the chaparral suggests a case of light competition similar to that described by McPherson and Muller (1967). After a previous fire, both evergreen and drought-deciduous species established side by side as seedlings, or in the case of Artemisia and Salvia, as both seedlings and crown sprouts (Westman et al. 1981). By 7 to 10 years, Ceanothus shrubs were tall enough to overtop the coastal sage scrub species. Eventually, the greater biomass and height of the Ceanothus shrubs interfered sufficiently with light reaching the smaller drought-decid- uous shrubs to suppress and eliminate them. The great attenuation of light by the canopy in mature stands of Ceanothus megacarpus has been documented by Schlesinger and Gill (1980), who found light levels well below that needed for net photosynthesis by the related chaparral shrub, C. greggiz. Indeed, the decrease of available light beneath the canopy during stand development in Ceanothus megacar- pus is manifest in the death of lower branches (Gray 1982).

Several results of McPherson and Muller (1967) are different from the situation described here. They reported that two cohorts of Cea- nothus cuneatus, aged 16 and 26 years, were present in their chaparral stand. Ceanothus shrubs in this study were even-aged. Ceanothus megacarpus seeds require heat alteration for germination (Hadley 1961),

1983] GRAY: COMPETITION IN COASTAL SAGE SCRUB 47

TABLE 2. PERCENT RELATIVE COVER AND ABSOLUTE DENSITY OF INDIVIDUAL SHRUBS IN THE COASTAL SAGE SCRUB. Standard deviations (S.D.) are provided for density values, n = 100. ! Grasses: Stipa lepida, Elymus condensatus, Bromus sp.; herbs: Castilleja affinis, Eriophyllum confertiflorum seedlings, Galium sp., Haplopappus squarrosus, Paeonia californica, Pityrogramma triangularis.

Evergreen (E) or Density drought- (individuals deciduous’ Relative per square Species (DD) leaves cover (%) meter) pop 10 Live plants Salvia leucophylla DD 49 0.98 1.24 Artemisia californica DD 29 0.81 1.64 Yucca whipplei E 7 0.07 0:32 Eriogonum parvifolium DD 4 0.20 0.40 Eriophyllum confertiflorum DD 2 0.55 O.32 Herbs and grasses’ — 9 — — Dead plants Artemisia californica DD — 0.13 0.43 Salvia leucophylla DD — 0.01 0.07

and successful germination is unlikely to occur between fires; hence, only a single cohort of C. megacarpus establishes after a fire. Mc- Pherson and Muller (1967) also found that most, if not all, of the Salvia shrubs in the chaparral understory were still alive and flowering after 26 years. The absence of any living Salvza shrubs in the C. megacarpus stand suggests that suppression at this site was more rapid. Annual production in C. megacarpus chaparral exceeds all reported values for California chaparral and other mediterranean-type ecosystems of the world (Gray 1982) and may facilitate a rapid overtopping of drought- deciduous shrubs.

HYPOTHESIS OF STAND DYNAMICS

Two mutually exclusive hypotheses can be proposed to explain the observed pattern in the chaparral: (1) The present stand of Ceanothus has persisted through many fires with a similar structure and biomass, and the dead, drought-deciduous species in the understory are only the remnants of early successional species that temporarily occupied the site. This successional relationship between coastal sage scrub and chaparral has been described in other chaparral communities (Cooper 1922, Wells 1962, Hanes 1971, 1977). (2) The present chaparral stand was occupied by a mature coastal sage scrub community immediately prior to the last fire. The latter community was completely eliminated by a single invasion of Ceanothus as a result of a large influx of seed before or immediately after the fire.

48 MADRONO [Vol. 30

The data and field observations are not consistent with either hy- pothesis. The existence of Artemisia and Salvia shrubs that arose from crown sprouts in the chaparral understory indicates that these indi- viduals had been present for at least two fire cycles. Hence, these species do not appear to be temporary, early successional occupants of the chaparral stand. It is also unlikely that the present chaparral stand developed en masse after the last fire, because there is no ad- jacent, upslope chaparral stand of Ceanothus to provide a large seed source (Fig. 1). Indeed, the only upslope chaparral stand is dominated by Adenostoma and it is separated from the Ceanothus stand by an 80-m strip of coastal sage scrub (Fig. 1).

A third hypothesis to explain the sharp boundary and dead coastal sage scrub species in the chaparral is the slow, progressive, invasion of the coastal sage scrub stand by Ceanothus after several fire cycles. In this scenario, a few isolated Ceanothus initially became established in the coastal sage scrub stand after a previous fire. These shrubs probably arose from seed that was dispersed by downslope movement or animal activity. Such isolated Ceanothus shrubs are now present around the edges of the coastal sage scrub stand (Fig. 1). These scat- tered shrubs then produced a large seed crop, which in turn gave rise to many more shrubs after the next fire. Ceanothus species in the chaparral have been observed to produce up to 835 seeds/m? in a single year (Keeley 1977). Given this potential for high seed production, only a few fire cycles may be necessary to permit the development of a relatively pure stand, which in turn would suppress and eliminate drought-deciduous shrubs.

The speed and extent of an invasion by Ceanothus would be affected by a variety of factors including variation in seed production, viability of stored seed in the soil, and the degree of seed predation. Ceanothus species in the chaparral vary greatly in annual seed output and appear to have very little seed storage potential in the soil (Keeley 1977). Hence, a fortuitous combination of an abundant seed crop followed by a fire and low seedling mortality would be necessary for this en- croachment by Ceanothus to occur.

The data suggest that Ceanothus shrubs are capable of invading coastal sage sites in the Santa Monica Mountains of southern Califor- nia, resulting in the extension of Ceanothus chaparral into lower ele- vations more typical of coastal sage scrub (Harrison et al. 1971). Thus, in contrast to a recent documentation of a coastal sage scrub/chamise chaparral boundary in interior San Diego County that has been stable for more than 60 years (Bradbury 1978), I suggest that the boundary between Ceanothus chaparral and coastal sage scrub is a dynamic one, arising from competitive interactions after fires.

ACKNOWLEDGMENTS

I thank Steve Trudell who reviewed an earlier version of this paper. This study was supported in part by grants to the author from the Academic Senate of the University

1983] GRAY: COMPETITION IN COASTAL SAGE SCRUB 49

of California, Santa Barbara and the California Native Plant Society. Support was also provided from NSF Grant DEB79-i1753 to W. H. Schlesinger while at Santa Barbara. I thank the California Department of Parks and Recreation for permission to use Leo Carillo State Beach Park for research.

LITERATURE CITED

BAUER, H. L. 1936. Moisture relations in the chaparral of the Santa Monica Moun- tains, California. Ecol. Monogr. 6:409-454.

BOARDMAN, N. K. 1977. Comparative photosynthesis of sun and shade plants. An- nual Rev. Pl. Physiol. 28:355—377.

BRADBURY, D. E. 1978. The evolution and persistence of a local sage/chamise com- munity pattern in southern California. Assoc. Pacific Coast. Geogr. Yearbook 40: 29-56.

CooPER, W. S. 1922. The broad-leaf sclerophyll vegetation of California. Publ. 319, Carnegie Institute of Washington, Washington, DC.

GRAY, J. T. 1982. Community structure and productivity in Ceanothus chaparral and coastal sage scrub of southern California. Ecol. Monogr. 52:415—435.

1983. Nutrient use by evergreen and deciduous shrubs of southern Califor-

nia. I. Community nutrient cycling and nutrient-use efficiency. J. Ecol. (In press).

and W. H. SCHLESINGER. 1981. Biomass, production, and litterfall in the coastal sage scrub of southern California. Amer. J. Bot. 68:24—33.

HADLEY, E. B. 1961. Influence of temperature and other factors on Ceanothus megacarpus seed germination. Madrono 16:132-138.

HANES, T. L. 1971. Succession after fire in the chaparral of southern California. Ecol. Monogr. 41:27-52.

1977. California chaparral. In M. G. Barbour and J. Majors, eds., Terrestrial vegetation of California, p. 417-469. Wiley-Interscience, NY.

HARRISON, A. T., E. SMALL, and H. A. Mooney. 1971. Drought relationships and distribution of two mediterranean-climate California plant communities. Ecology 52:869-875.

KEELEY, J. E. 1975. Longevity of nonsprouting Ceanothus. Amer. Midl. Naturalist 93: 505-507.

1977. Seed production, seed populations in soil, and seedling production after fire in two congeneric pairs of sprouting and non-sprouting chaparral shrubs. Ecol- ogy 58:820-829.

KIRKPATRICK, J. B. and C. E. HUTCHINSON. 1977. The community composition of California coastal sage scrub. Vegetatio 35:21—33.

McPHERSON, J. K. and C. H. MULLER. 1967. Light competition between Ceanothus and Salvia shrubs. Bull. Torrey Bot. Club 94:41-55.

SCHLESINGER, W. H. and D. S. GILL. 1980. Biomass, production and changes in the availability of light, water, and nutrients during the development of pure stands of the chaparral shrub, Ceanothus megacarpus, after fire. Ecology 61:781—789.

WELLS, P. V. 1962. Vegetation in relation to geological substratum and fire in the San Luis Obispo Quadrangle, California. Ecol. Monogr. 32:79-103.

WESTMAN, W. E. 1981. Factors influencing the distribution of species of California coastal sage scrub. Ecology 62:170-184.

, J. F. OPLEARY, and G. P. MALANSON. 1981. The effects of fire intensity,

aspect and substrate on post-fire growth of Californian coastal sage scrub. In N.

S. Margaris and H. A. Mooney, eds., Components of productivity of Mediterra-

nean regions—basic and applied aspects, p. 151-180. Dr. W. Junk, The Hague,

Netherlands.

EVIDENCE OF SALINITY-INDUCED ECOPHENIC VARIATION IN CORDGRASS (SPARTINA FOLIOSA TRIN.)

DANIEL J. CAIN U.S. Geological Survey, MS65, Menlo Park, CA 94025

H. THOMAS HARVEY Department of Biological Sciences, San Jose State Univ., San Jose, CA 95192

ABSTRACT

Results of culturing two height forms of Spartina foliosa in NaCl-treated nutrient solutions indicate that they are ecophenes. Growth was best in moderately saline so- lution and inhibited in fresh water and in a 1.2 osmolal (35 ppt) solution. Comparison of these results with soil salinity from areas supporting populations of each form suggest that the height of S. foliosa is influenced by local soil salinity conditions.

Spartina foliosa Trin. is a dominant plant species of the lower and mid-littoral zones of California salt marshes (Macdonald and Barbour 1974). The lower limit of its distribution is thought to be controlled by tidal inundation (Hinde 1954, Rowntree 1973). Its upper limit of distribution, which generally coincides with the mean high water (MHW) level, is governed by high soil salinity (Mahall and Park 1976b). Height and biomass of plants growing in this area of the marsh are generally less than in plants growing at lower intertidal elevations (Purer 1942, Atwater and Hedel 1976, Mahall and Park 1976a).

A population of S. foliosa in which adults grow only to 20-30 cm in height occurs along the eastern shoreline of San Francisco Bay. This marsh, located at the mouth of the Alameda River, is situated relatively high in the intertidal zone and is probably a remnant of a more extensive, pre-existing marsh (Mason 1976).

The difference in height between plants growing at high and low intertidal areas has led to the recognition of two forms of S. foliosa (Anonymous, 1976). The “robust” form is stout culmed, 0.3-1.2 m tall, and inhabits the lower littoral zone. The “dwarf” form is 0.2—0.3 m tall and typically occurs in the mid-littoral zone. The height dis- tinction between the forms was adopted from criteria established for height forms of Spartina alterniflora (Adams 1963, Cooper 1974), a closely related species (Mobberley 1956) that occurs as the dominant vascular plant species of the lower and mid-littoral zones of East and Gulf Coast salt marshes.

The existence of height forms of Spartina sp., each occupying rather

MADRONO, Vol. 30, No. 1, pp. 50-62, 28 January 1983

1983] CAIN AND HARVEY: VARIATION IN SPARTINA 51

distinct elevational zones within the marsh, has generated studies to determine if the forms are ecotypes, and thus genetically distinct, or ecophenes, and thus genetically homogeneous. Parnell (1976) deter- mined that 2x = 60 for both the robust and dwarf forms of S. foliosa. Based upon chromosome number, then, there is no evidence that these two forms are different polyploid races. However, the same chromo- some number for both forms does not negate the existence of ecotypes (Clausen et al. 1941). Based upon results of a field transplant experi- ment from which data were collected for more than a year, Harvey (1976) concluded that the forms were ecophenes and the variation in height was a physiological response to environmental gradients asso- ciated with tidal elevation.

With the exception of elevation, no environmental factors were mea- sured in the study by Harvey (1976), and it is therefore not possible to correlate morphological variation with any specific environmental gradient(s) that may exist as a function of tidal elevation.

It is well documented that soil salinity is a major factor influencing growth and plant distribution within salt marshes (Chapman 1938, 1939; Mall 1969, Mahall and Park 1976b, Penfound and Hathaway 1938, Purer 1942). Furthermore, Mooring et al. (1971) and Nestler (1977) have shown that height of S. alterniflora is inversely related to salinity, suggesting that the height forms of this species are ecophenes.

In this study, the genecologic relationship of dwarf and robust S. foliosa was further investigated by examining the relative effect of salinity on these height forms under controlled laboratory conditions. It was hypothesized that the height forms are ecophenes and that the morphological dissimilarity observed in the field would vanish when both forms were exposed to a uniform, controlled environment. In order to relate morphological responses to actual field conditions, an assessment was made of the level of soil salinity each form was exposed to during a growing season.

METHODS

Soil samples and plants were collected from two marshes. Palo Alto marsh is located on the western shore of San Francisco Bay at ap- proximately 37°27'N, 122°06’W. Spartina foliosa and Salicornia vir- ginica L. are co-dominant. Robust S. foliosa (1-1.5 m tall) is found in monospecific stands at the low intertidal elevations and along creek channels. There appears to be a clinal variation in height associated with intertidal elevation because at the Spartina—Salicornia ecotone (roughly MHW), S. foliosa is typically 20-50 cm tall.

Alameda Creek marsh (37°36'N, 122°07’W) is located on the eastern shore of San Francisco Bay at the mouth of Alameda Creek. The marsh is dominated by Salicornia virginica and dwarf Spartina foliosa (adult plants are 20-30 cm tall). Spartina occurs most extensively as

52 MADRONO [Vol. 30

a monospecific stand along the shoreward 10 m of the marsh. It is also found hugging the edges of shallow tidal creeks that traverse the marsh.

Soil samples were taken in 1977 at the beginning (May) and end (October) of the growing season from three 3 X 6 m plots staked out in each marsh. The plots were placed so that discrete samples could be taken along the portion of the intertidal zone inhabited by S. fo- liosa. At Palo Alto, plot 1 (PA 1) was located within a stand of robust plants at the lower limit of intertidal distribution of S. folzosa. Plot 2 (PA 2) was located adjacent to a tidal creek within a stand of robust S. foliosa. This area was higher in the intertidal zone than plot 1. Plot 3 (PA 3), the highest intertidal area sampled, was located at the Spar- tina—Salicornia ecotone. At Alameda Creek, the sample plots were located along a transect that ran the width of the marsh. Plot 1 (AC 1) was located within the strip of S. foliosa that occupied the shore- ward 10 m of the marsh. Plot 2 (AC 2) was at the Spartina—Salicornia ecotone, roughly 4 m from plot 1. Plot 3 (AC 3) was located within a small stand of S. foliosa that was restricted to the edges of a salt pan and an adjoining tidal creek. This pan was in the high marsh, an area dominated by Salicornia.

Soil samples were collected with a stainless steel soil corer with a 2 cm inner diameter. The cores were immediately sectioned horizontally into O—-5 cm, 5—15 cm, and 15-25 cm soil layers and the sections were sealed separately in plastic bags. The salinity of the root zone was calculated as the mean salinity of the 5-15 cm and the 15-25 cm soil layers. The determination of soil salinity was modified from Mahall and Park (1976b): water-soluble salts were extracted from a soil sample that had been dried at 100°C, and the osmolality of the extract was measured on a Wescor-model 5100 vapor pressure osmometer. Salinity of the original soil solution was calculated as osmole kg’ H,O.

Dwarf plants were collected from Alameda Creek on 17 March 1978, and robust plants were collected from Palo Alto on 22 March 1978. At Alameda Creek, all the plants were collected along the shore- ward edge of the marsh where plot 1 was located. Plants from Palo Alto were collected from the areas where plots 1 and 2 were located. Alameda Creek was selected as the sole source of dwarf plant material. If the forms are ecotypes, then the robust form appears to be com- pletely selected against at Alameda Creek. Thus, this population may represent a relatively homogeneous genetic stock of dwarf individuals. If both the dwarf, i.e., plants at the Spartina—Salicornia ecotone, and the robust form were collected from Palo Alto marsh, the expression of genetic differences between them may be diminished due to the greater potential for gene flow between sympatric forms. In order to collect young dwarf and robust plants of roughly the same age, plants approximately the same height with two expanded leaves were pref- erentially selected from both marshes.

1983] CAIN AND HARVEY: VARIATION IN SPARTINA 53

All the plants collected for this study appeared to be new shoots sprouting from underground rhizomes, the species’ primary means of reproduction. Asexual reproduction assures that the collected plants were representative of the respective forms observed at each marsh. The parents could not be determined, thus the samples were random- ized with respect to the intrinsic genotypic variation within each pop- ulation.

The plants were carefully uprooted so as to leave soil around the roots. Soil was later rinsed from the roots with tapwater in the labo- ratory. The plants were immediately rooted in vermiculite, and kept in a greenhouse until May, by which time they had fully recovered from transplanting (a well-developed root system was established, and the shoots had begun to grow).

On 12 May 1980, plants of each form were distributed evenly among four tubs, each containing 20 | of full strength nutrient solution (Mach- lis and Torrey 1956). Because Spartina sp. may require high levels of iron for successful growth (Adams 1963), the concentration of iron (as FeEDTA) was increased from 5 ppm to 10 ppm. Each solution was mixed and aerated by bubbling air through two plastic air diffusers. The air was supplied at a uniform rate by a filtered manifold system. Concentrations of 0.4 osmole kg-' H,O (11.7 ppt), 0.8 osmole kg"! H,O (23.4 ppt), and 1.2 osmole kg ! H,O (35.1 ppt) were established in three tubs by adding reagent grade NaCl at a rate of 0.2 osmole kg! H.O every five days (Mahall and Park 1976b). Results of the field soil sampling were used to set the upper limit of the salinity range. The remaining solution consisted of nutrient solution only and served as a control against which salinity effects could be compared. The measured osmolality of this solution was 0.054 osmolal. The salinity of the solutions was monitored, and distilled water and/or NaCl were added as needed to maintain the proper concentrations. Nutrients were added at half strength every four weeks to supplement losses. The mean pH values for the control and the 0.4, 0.8, and 1.2 osmolal treatments were 6.3, 6.8, 7.0, and 6.7, respectively. Ambient air tem- peratures were maintained at 26°C, and relative humidity at 50%.

At the beginning of the experiment, 19 dwarf and 20 robust plants were measured for height, dry weight, leaf area, and leaf weight ratio (g leaves/g whole plant). Height was measured from the first visible node on the culm directly above the roots to the tip of the longest leaf. Leaf area was determined by treating each leaf as an isosceles triangle (Nestler 1977). Leaf weight ratio was calculated from the dry weight. The material was dried at 80°C for at least 24 hours in a forced draft oven. Plants in the culture solutions were harvested after 12 weeks.

One-way and two-way analysis of variance was used for statistical analysis of the data. Data for leaf area and leaf weight ratio were normalized by square root and arcsine transformation, respectively (Sokal and Rohlf 1969). In cases where the variances of the samples

54 MADRONO [Vol. 30

TABLE 1. HEIGHT, DRY WEIGHT, LEAF AREA, AND LEAF WEIGHT RATIO OF DWARF AND ROBUST FORMS OF Spartina foliosa PRIOR TO TREATMENT IN CULTURE SOLUTION.

Dwarf (n = 19) Robust (n = 20) Height, cm (x + S.E.) DAL ee 23.6 “2-11 Dry wt., g (x + S.E.) 0.307 + 0.068 0.369 + 0.039 cm? leaf~! (x; 95% C.L.) 2.99; 2.53-3.50 3.99; 2.89-3.96 Leaf wt. ratio (x; 95% C.L.) 0.239; 0.198—0.283 0.152; 0.132-0.172

being compared were not homogeneous, the Mann-Whitney test was used (Sokal and Rohlf 1969). Differences were considered significant when a < 0.05.

RESULTS

Height, dry weight, and individual leaf area were not significantly different (p > 0.05) between the robust and the dwarf form when the culture experiment was started (Table 1). The leaf weight ratio of the dwarf form was significantly higher (p < 0.001) than that of the robust form. This difference was partially attributed to the heavier culm characteristic of the robust form. Additionally, the robust plants had a more extensive root and rhizome system, decreasing the dry weight of the leaves relative to the whole plant.

Survival of the two forms was similar after 12 weeks exposure to the same salinity (Table 2). Although the concentration of Fe was increased to 10 ppm, symptoms of Fe deficiency began to appear after about 45 days. Chlorosis was exhibited by all plants, but it was most pronounced in the plants in freshwater and the 0.4 osmolal treatment. Iron deficiency symptoms have also been described for cultured adult and seedling S. alterniflora (Adams 1963, Mooring et al. 1971). At present, it is not known if these observations are the result of a phys- ico-chemical interaction between Fe and NaCl (Adams 1963), whereby

TABLE 2. SURVIVAL OF DWARF AND ROBUST FORMS OF Spartina foliosa GROWN IN SALINE CULTURE SOLUTION.

Number of surviving plants

Treatment Dwarf Robust Control 10 - 0.4 osmolal 8 9 0.8 osmolal 17 16

1.2 osmolal 12 12

1983] CAIN AND HARVEY: VARIATION IN SPARTINA 35

Fe availability to the plant is enhanced at high ionic strengths, or if there is a physiological requirement for one or both NaCl ions (Moor- ing et al. 1971). Mooring et al. (1971) reported that chlorosis was relieved by foliar application of ferrous sulfate; however, in our study, foliar spraying of FeEDTA did not alleviate leaf yellowing.

Height and dry weight (Figs. 1, 2) were greatest at 0.4 osmolal for the robust form and 0.8 osmolal for the dwarf form, suggesting that they may possess different salinity optima. However, the differences in height and dry weight between the forms at any given concentration were not significant. Height and dry weight did vary significantly with salinity. There were no significant interaction effects of salinity and form on height, the only character we were able to analyze by two- way ANOVA.

The maximum leaf area for the robust and dwarf forms (Table 3) occurred in the 0.4 osmolal and the 0.8 osmolal solutions, respectively, coincident with the maximum values for height and dry weight. The forms were significantly different at 0.4 osmolal (0.01 < p < 0.05), but not in freshwater, or in the 0.8 and 1.2 osmolal solutions. For each form, there were significant differences with salinity. Leaf area of the dwarf form was significantly greater at 0.4 and 0.8 osmolal than in freshwater or at 1.2 osmolal. Leaf area of the robust form was significantly greater at 0.4 osmolal than at 1.2 osmolal.

Differences in the leaf weight ratios between the forms was not significant (Fig. 3). This character was inversely related to salinity. Leaf weight ratio was significantly less in the 1.2 osmolal solution than in the less saline solutions.

The salinity of the root zone (5-25 cm) for Palo Alto and Alameda Creek marshes is given in Table 4. Generally, soil salinity was higher within the Alameda Creek marsh. In May, the salinity of PA 1 and 2 was significantly less than any of the three locations sampled within Alameda Creek marsh. However, the salinity of PA 3, the highest intertidal area sampled, was equal to the salinity of AC 1. Soil salin- ities were relatively stable throughout the Alameda Creek marsh be- tween May and October, whereas at Palo Alto the concentration of salts of plots 2 and 3, the two higher intertidal areas, increased to levels approximately equal to those of AC 1 and 3. This type of sea- sonal variation is well-documented for temperate zone coastal salt marshes (Chapman 1939, 1940; Mahall and Park 1976b, Purer 1942).

DISCUSSION

The classic approach to studying ecotypic variation within plant species is to collect specimens from populations that are phenotypically distinct under natural conditions and then grow them together under uniform conditions (Clausen et al. 1941, Goodman 1973, McMillan 1959). Any differentiation in the measured characteristics among pop-

56 MADRONO [Vol. 30

70

65

60

318.

50

HEIGHT IN CM

45

40

35

30 0.4 0.8 eZ

OSMOL/KG HO

Fic. 1. Height (Y + S.E.) of dwarf (A) and robust (CJ) forms of Spartina foliosa grown in NaCl-treated nutrient solution.

O

1983] CAIN AND HARVEY: VARIATION IN SPARTINA S7

MEAN DRY WEIGHT IN GRAMS

0 0.4 0.8 1.2 OSMOL/KG H50

Fic. 2. Dry weight (Y + S.E.) of dwarf (A) and robust (C) forms of Spartina foliosa grown in NaCl-treated nutrient solution.

58 MADRONO [Vol. 30

TABLE 3. MEAN LEAF AREA (CM? LEAF ~!) WITH 95% CONFIDENCE LIMITS OF THE DWARF AND ROBUST FORMS OF Spartina foliosa GROWN IN SALINE CULTURE SOLUTION.

Dwarf Robust

Treatment x; 95% C.L. x; 95% C.L. 0.0 7.08; 6.00—8.29 8.64; 7.13—-10.2 0.4 osmolal 7.51; 6.20—8.94 10.1; 8.35-12.0 0.8 osmolal 9.49; 8.47-10.5 8.53; 7.29—-9.86 1.2 osmolal 7.29; 6.00—8.76 6.76; 5.48-8.24

0.4 S03 = <6 am |— ae o LLJ = A LL < ui 0.2 —

@) O 0.4 0.8 teZ

OSMOL/KG H50

Fic. 3. Leaf weight ratio (Y + S.E.) of dwarf (A) and robust (LJ) forms of Spartina foliosa grown in NaCl-treated nutrient solution.

1983] CAIN AND HARVEY: VARIATION IN SPARTINA 59

TABLE 4. SOIL SALINITY (x + S.E.) AS OSMOLE KG! H,O OF ROOT ZONE OF PALO ALTO (PA) AND ALAMEDA CREEK (AC) MARSHES DURING THE 1977 GROWING SEASON. a: n = 3; n = 4 for all others.

May October

Plot Plot Station 1 2 3 1 2 3 PA 0.89 + 0.01 0.99 + 0.01 1.05 + 0.03 0.89 + 0.022 1.09 + 0.04 1.18 + 0.02 AC 1.18 220.07 1:37 227002 153022. 003° 1,07 4.0.02 141-2 0,06: 1.23.) 0:02

ulations is assumed to be genetic. The results of the culturing exper- iment in this study indicate that the dwarf and robust forms of S. foliosa are not salinity ecotypes. When the experiment was started, dwarf and robust plants displayed different leaf weight ratios. How- ever, by the end of the experiment, this distinction no longer existed. With the exception of the difference in leaf area between the forms grown at a salinity of 0.4 osmolal, dwarf and robust were not distin- guishable by any of the characters measured. Furthermore, the height of dwarf S. foliosa grown in the laboratory exceeded the height of dwarf plants in nature, suggesting that the growth of plants at Ala- meda Creek is inhibited by unfavorable environmental conditions.

Significant differences in the responses of plants were associated with salinity. Survival, height, biomass and leaf area were greatest when the plants were grown under moderately saline conditions. How- ever, in freshwater and the 0.4 osmolal solution, iron was apparently less available for plant uptake, making the direct assessment of the effect of NaCl on the growth of S. foliosa in those solutions difficult. Iron chlorosis was not severe in the two highest NaCl concentrations, indicating that iron was more available and not limiting plant growth. Inhibition of plant growth occurred over a narrow range of salinity between 0.8 and 1.2 osmolal. This inhibition was probably due to energy expended maintaining the internal salt balance, a process reg- ulated by actively secreting salts through salt glands. Mahall and Park (1976b) found that shoot growth of cultured S. foliosa was significantly reduced at concentrations greater than 0.6 osmole kg ' H,O. The reduction in leaf weight ratio with increasing salinity may be an aspect of a common strategy in the adjustment of a plant to salinity by which the transpirational surface area is decreased relative to the water ab- sorbing surface area (Bernstein and Hayward 1958).

Because soil salinities were recorded at the beginning and end of the growing season, we have no detailed information on how long plants from the two marshes and from different intertidal areas of the same marsh were exposed to particular salinities. These data would be valuable if growth rate is an integrated response to salt concentra-

60 MADRONO [Vol. 30

tion over time. Assuming that it is, and using the available data, soil salinity at Alameda Creek appeared to remain relatively high through- out the growing season, suggesting that plant growth may be inhibited by prolonged salinity stress. At Palo Alto, soil salinity increased with increasing distance from the shoreward edge of the marsh, and, unlike Alameda Creek, displayed a seasonal increase that was increasingly more pronounced at higher intertidal areas. Salinity of the lowest in- tertidal area, PA 1, was seasonally constant, but at PA 2 salinity increased in October to concentrations equal to those recorded at Ala- meda Creek. However, the duration of exposure to the October con- centrations may have been relatively brief. Plants at PA 3 (where height and biomass were reduced relative to plants at PA 1 and PA 2) were continuously exposed to concentrations as high as those re- corded at Alameda Creek. Thus soil salinity conditions, at least in terms of concentration and duration of exposure, were similar between PA 3 and Alameda Creek, the two areas where dwarf plants occur.

In this study, only one environmental factor, salinity, was exam- ined. It is rather unlikely that single cause and effect relationships affecting variation are prevalent in nature (Gould and Johnston 1972). Also, the occurrence of polygenic inheritance systems (Nobs and Hies- ey 1957) indicates that the physiological and morphological response of an individual may depend upon the interaction of several environ- mental components within the genotype. Therefore, it cannot be dis- counted that the dwarf and robust forms would not segregate under a different set of factors. Nonetheless, the salinity effects observed for cultured plants complement the findings of the field survey: dwarf plants were associated with soils that displayed relatively high soil salinity throughout the growing season, whereas robust plants oc- curred in less saline soils. The results of this study, consistent with those of Harvey (1976) for S. foliosa and Mooring et al. (1971) and Nestler (1977) for S. alterniflora, indicate that the height forms of S. foliosa are ecophenes, and that the phenotypic expression of the species is partially a function of soil salinity.

ACKNOWLEDGMENTS

We would like to thank Dr. M. G. Barbour and the journal’s reviewers for their criticisms and suggestions on earlier drafts of the manuscript.

LITERATURE CITED

ApAMsS, D. A. 1963. Factors influencing vascular plant zonation in North Carolina salt marshes. Ecology 44:445—456.

ANONYMOUS. 1976. In Dredge disposal study San Francisco Bay and estuary. Ap- pendix K. Marshland development. U.S. Army Corps of Engineers. p. 1—61. ATWATER, B. F. and C. W. HEDEL. 1976. Distribution of seed plants with respect to tide levels and water salinity in the natural tidal marshes of northern San Fran-

cisco Bay estuary, California. U.S. Geol. Surv. Open File Report 76-389.

1983] CAIN AND HARVEY: VARIATION IN SPARTINA 61

BERNSTEIN, L. and H. E. HAYWARD. 1958. Physiology of salt tolerance. Annual Rev. Pl. Physiol. 9:25—46.

CHAPMAN, V. J. 1938. Studies in salt marsh ecology. Sections I to III. J. Ecol. 26: 144-179.

1939. Studies in salt marsh ecology. Sections IV and V. J. Ecol. 27:160-—201.

1940. Studies in salt marsh ecology. Sections VI and VII. Comparison with marshes on the east coast of North America. J. Ecol. 28:118—152.

CLAUSEN, J., D. D. KECK, and W. M. HIEsEy. 1941. Regional differentiation in plant species. Amer. Naturalist 75:231—250.

CooPER, A. W. 1974. Salt marshes. Jn H. T. Odum, B. J. Copeland, and E. A. McMahan, eds., Coastal ecological systems of the United States, Vol. II, p. 55- 98. Conservation Foundation, Washington, DC.

GOODMAN, P. J. 1973. Physiological and ecotypic adaptations of plants to salt desert conditions in Utah. J. Ecol. 61:473-494.

GOULD, S. J. and R. F. JOHNSTON. 1972. Geographic variation. Annual Rev. Ecol. Syst. 3:457-498.

Harvey, H. T. 1976. Spartina foliosa survival and growth along elevational tran- sects. (Memorandum) Jn Dredge disposal study San Francisco Bay and estuary. Appendix K. Marshland development. U.S. Army Corps of Engineers. Enclosure 3. San Francisco.

HINDE, H. P. 1954. The vertical distribution of salt marsh phanerograms in relation to tide levels. Ecol. Monogr. 24:209-225.

MACDONALD, K. B. and M. G. BARBOUR. 1974. Beach and salt marsh vegetation of the North American Pacific Coast. Jn R. J. Reimold and W. H. Queen, eds., Ecology of halophytes, p. 175-234. Academic Press, NY.

MAcHLIs, L. and J. G. TORREY. 1956. Plants in action. W. H. Freeman and Co., San Francisco.

MAHALL, B. E. and R. B. PARK. 1976a. The ecotone between Spartina foliosa Trin. and Salicornia virginica L. in salt marshes of Northern San Francisco Bay. I. Biomass and production. J. Ecol. 64:421—433.

and 1976b. The ecotone between Spartina foliosa Trin. and Salicor- nia virginica L. in salt marshes of Northern San Francisco Bay. II. Soil water and salinity. J. Ecol. 64:793-809.

MALL, R. E. 1969. Soil—water-salt relationships of waterfowl food plants in the Suisun Marsh of California. State of California. The Resources Agency Department of Fish & Game. Wildlife Bull. No. 1.

Mason, H. L. 1976. Marsh studies. Jn Dredge disposal study San Francisco Bay and estuary. Appendix K. Marshland development. U.S. Army Corps of Engineers. Enclosure 1. San Francisco.

McMILLAN, C. 1959. The role of ecotypic variation in the distribution of the central grassland of North America. Ecol. Monogr. 24:285-308.

MOoBBERLEY, D. G. 1956. Taxonomy and distribution of the genus Spartina. Iowa State J. Sci. 30:471-574.

Moor inc, M. T., A. W. Cooper, and E. D. SENECA. 1971. Seed germination re- sponse and evidence for height ecophenes in Spartina alterniflora from North Car- olina. Amer. J. Bot. 58:48—55.

NESTLER, J. 1977. Interstitial salinity as a cause of ecophenic variation in Spartina alternifilora. Estuarine Coastal Mar. Sci. 5:707—714.

Noss, M. A. and W. M. HIESEY. 1957. Studies on differential selection in Mimulus. Carnegie Inst. Wash. Year Book 56:291-292.

PARNELL, D. R. 1976. Chromosome numbers in growth forms of Spartina foliosa Trin. In Dredge disposal study San Francisco Bay and estuary. Appendix K. Marshland development. U.S. Army Corps of Engineers. Enclosure 2. San Fran- cisco.

PENFOUND, W. T. and E. S. HATHAWAY. 1938. Plant communities in the marshlands of southeastern Louisiana. Ecol. Monogr. 8:1—56.

62 MADRONO [Vol. 30

PuRER, E. A. 1942. Plant ecology of the coastal salt marshlands of San Diego County, California. Ecol. Monogr. 12:81—111.

ROWNTREE, R. A. 1973. Morphological change in a California estuary: sedimentation and marsh invasion at Bolinas Lagoon. Ph.D. dissertation, Dept. Geology, Univ. California, Berkeley.

SOKAL, R. R. and F. J. ROHLF. 1969. Biometry. W. H. Freeman and Co., San

Francisco.

1983] NOTEWORTHY COLLECTIONS 63

NOTEWORTHY COLLECTIONS

CALIFORNIA

PEDICULARIS DUDLEYI Elmer (SCROPHULARIACEAE).—San Luis Obispo Co., mesa s. of Arroyo de la Cruz, 1.6 kme. CA 1, 18.5 km n. San Simeon, 16 Mar 1980, Riggins 1195 (OBI, JEPS); 11 Apr 1981, Riggins 1208 (OBI, JEPS). (Determined by L. R. Heckard)

Significance. A range extension of 80 kms. from Little Sur River, Monterey Co. The species is considered rare and endangered (CNPS Inventory, 1980). The chromosome number has been determined by D. J. Keil as m = 8.—RHONDA RIGGINS, Biological Sciences Dept., California Polytechnic State Univ., San Luis Obispo 93407.

IDAHO

ASTRAGALUS GILVIFLORUS Sheld. (FABACEAE).—Clark Co., s. end of Beaverhead Mts. near Reno Point (T8N R31E S15), 1646 m, 25 May 1981, S. Goodrich 15431 (BRY, ID, NY, OGDF). (Verified by R. Barneby, NY)

Significance. First record for ID and extension sw. of ca. 190 km from Madison and Park co’s., MT.

HACKELIA DAVISII Cronq. (BORAGINACEAE).—Lemhi Co., Salmon River Mts., can- yon bottom along Camas Cr. between Forge Cr. and Dry Gulch (T18N R16E 821-22), 1434 m, 28 May 1981, S. Goodrich & E. W. Tisdale 15496 (BRY, ID, NY, OGDF) (Verified by A. Cronquist, NY); granite talus along trail, Camas Cr., between Forge Cr. and Little Dry Cr. with Pseudotsuga menziesii (T18N R16E S15 sw.%), 1464 m, 7 Jul 1981, D. Henderson & A. Cholewa 5989 (ID).

Significance. This narrow endemic, currently listed in Cat. 1, Federal Register, 15 Dec. 1980, was known only from the general area near the confluence of the main Salmon Riv. and the Middle Fk. on moist, limestone cliffs associated with Pinus ponderosa (Steele, R. 1981, Vasc. Plt. Spp. of Concern in Idaho. Univ. Idaho College of For., Wildl., & Range Sci., FWR Expt. Sta. Bull. 34. p. 20) and along Panther Cr., vic. Cobalt (R. Carr, pers. comm.). These new collections establish its presence on a granitic substrate and association with Pseudotsuga menziesii ca. 45 km s. of the type locality, and suggest the likelihood of additional populations occurring elsewhere within the Salmon River drainage.—SHEREL GOODRICH, USDA Forest Service, Intermountain Forest and Range Experiment Station, Ogden, UT 84401 (stationed in Provo, UT, at Shrub Sciences Laboratory); and DOUGLASS HENDERSON and ANITA CHOLEWA, Dept. Biological Sciences, Univ. Idaho, Moscow 83843.

LESQUERELLA KINGII S. Wats. var. COBRENSIS Roll. & Shaw (BRASSICACEAE).— Butte Co., Idaho National Engineering Laboratory, 6.4 km se. of CFA (T2N R30E S22 se.% of ne.%), 1494 m, 1 Jun 1981, A. Cholewa 632 (ID); vic. Middle Butte (T2N R32E 821 sw.% of nw.%), 1615 m, 18 Jun 1981, A. Cholewa 787 (GH, ID); ca. 5 km n. of Middle Butte (T2N R32E S7 sw.% of sw.%), 1615 m, 18 Jun 1981, A. Cholewa 789 (GH, ID). (Collections indicated GH identified by R. Rollins, GH, 1981)

Significance. First records for ID and extension ne. of ca. 310 km from Elko Co., NV.

ASTRAGALUS KENTROPHYTA Gray var. JESSIAE (Peck) Barneby (FABACEAE).—Butte Co., Idaho National Engineering Laboratory, se. end of Lemhi Range (T6N R30E S23 n.42), 1606 m, 17 Jun 1981, A. Cholewa & D. Henderson 777 (ID, NY). (Det. by R. Barneby, NY, 1981)

Significance. Previously known in Idaho only from Owyhee Co., and an extension ne. of ca. 252 km.

64 MADRONO [Vol. 30

GILIA POLYCLADON Torrey (POLEMONIACEAE).—Butte Co., Idaho National Engi- neering Laboratory, se. end of Lemhi Range (T6N R30E S35 sw.% of sw.%), 1508 m, 16 Jun 1981, A. Cholewa 759 (CS, ID). (Det. by D. Wilken, CS, 1981)

Significance. Reported from sagebrush zones of sw. ID (Davis, R. J. 1952, Flora of Idaho), but without locations.—ANITA F. CHOLEWA and DouGLass HENDERSON, Dept. Biological Sciences, Univ. Idaho, Moscow 83843.

ASTRAGALUS LEPTALEUS Gray (FABACEAE).—Custer Co., Boulder Mts., N. Fk. Big Lost River (T7N R19E 823 ne.%), 2191 m, 31 Jul 1981, S. L. Caicco & J. Civille 287 (ID, NY). (Det. by R. Barneby, NY)

Significance. Represents only the second known site in ID and the first collection in the past 30 years.

PENSTEMON PROCERUS Dougl. var. FORMOSUS (A. Nels.) Cronq. (SCROPHULARIA- CEAE).—Custer Co., Pioneer Mts., head of Bellas Gulch (T5N R21E S6 se.%), 3226 m, 15 Jul 1981, S. L. Caicco & J. Civille 210 (ID, NY) (Verified by N. Holmgren, NY); Lake Creek drainage, % km ese. of southernmost lake in upper basin (T4N R22E S4 se.%), 3104 m, 21 Jul 1981, S. L. Caicco & J. Civille 256 (ID); Surprise Valley, near outlet of upper lake, ca. 1.3 km n. of Standhope Pk. (T6N R21E S31 sw.%), 3089 m, 27 Jul 1981, D. Henderson & C. Wellner 6024 (ID); ridge, e. side Betty Lake, 1.4 km e. of Standhope Pk. (T5N R21E S6 se.%), 3165 m, 3 Aug 1981, S. L. Caicco & J. Civille 302 (ID).

Significance. First records of this taxon from ID and extensions ese. of ca. 300 km from Baker Co., OR.—STEVEN CAICCO, JANIE CIVILLE, and DOUGLASS HENDERSON, Dept. Biological Sciences, Univ. Idaho, Moscow 83843.

PARNASSIA KOTZEBUEI Cham. (SAXIFRAGACEAE).—Custer Co., Lost River Range, lakeshore near head of w. br. E. Fk. Pahsimeroi River (TON R23E 826 nw. of nw.%), 2967 m, 10 Aug 1979, S. & P. Brunsfeld 1359 (ID, UC) (Verified by R. B. Phillips, UC); Pioneer Mts., cliffs s. of Kane Lake (T5N R19E S1 s.%), 2891 m, 30 Jul 1981, S. L. Caicco & J. Civille 280 (ID); upper Wildhorse Cr. drainage, ca. 1 km w. of Arrowhead Lake (T5N R20E S21 s.%), 2860 m, 14 Aug 1981, S. L. Caicco & J. Civille 340 (ID).

Significance. First records for ID.—STEVEN BRUNSFELD, College of Forestry, Wild- life and Range Sciences, Univ. Idaho, Moscow 83843; and STEVEN CaIcco and DouG- LASS HENDERSON, Dept. Biological Sciences, Univ. Idaho, Moscow 83843.

MOoNTANA-IDAHO

ERIGERON RADICATUS Hook. (ASTERACEAE).—MT, Deer Lodge Co., Anaconda-Pin- tlar Wilderness, Little Rainbow Mt., 1.6 km w. of Storm Lake (T4N R13W S31 n.'4), 3018 m, 8 Jul 1972, Lackschewitz 3770 (MONTU, NY, WTU); Madison Co., Gravelly Range, crest of Red Hill (T10S R2E $17), 2830 m, 5 Jul 1979, Lackschewitz 8989 (MONTU); Flathead Co., Bob Marshall Wilderness, Flathead Mts., North Chinese Wall, s. of Sock Lake (T24N R11W S31 w.%), 2500 m, 26 Jul 1979, Lackschewitz 9102 (MONTU, NY, WTU). ID, Butte Co., e. slope Lemhi Range, Meadow Canyon area, Summit Pk. 10858 (TION R28E S4), 3309 m, 14 Jul 1975, D. Henderson 2636 (ID); Lemhi Co., s. Beaverhead Mts., wsw. ridge of Italian Pk. (T12N R10W S18), 3030 m, 10 Jul 1977, S. & P. Brunsfeld 464 (ID, NY); Custer Co., e. slope Lost River Range, upper Merriam Lake basin (TON R23E S17), 2909 m, 21 Jul 1978, D. Henderson, S. & P. Brunsfeld 4692 (ID). (Collections deposited at NY det. by A. Cronquist)

Significance. The Lackschewitz collections represent the first record for MT and contiguous US; the ID collections are first records for that state-—KLAUS LACKSCHEW-

1983] NOTEWORTHY COLLECTIONS 65

1Tz, Dept. Botany, Univ. Montana, Missoula 59812; DoUGLASS HENDERSON, Dept. Biological Sciences, Univ. Idaho, Moscow 83843; and STEVEN BRUNSFELD, College of Forestry, Wildlife, and Range Sci., Univ. Idaho, Moscow 83843.

ANNOUNCEMENT

LAWRENCE MEMORIAL AWARD

The Award Committee of the Lawrence Memorial Fund is pleased to announce that Ms. Janet R. Sullivan of the University of Oklahoma was selected to receive the 1982 Lawrence Memorial Award. A student of Dr. James R. Estes, Ms. Sullivan is inves- tigating the taxonomy, ecology, and evolution of the genus Physalis (Solanaceae). She will use the proceeds of the Award in travel to the southeastern United States and the Gulf Coast for field studies.

Nominations for the 1983 Award are now being entertained. Major professors are urged to submit letters in behalf of outstanding doctoral students who have achieved official candidacy for their degrees, will be conducting dissertation research in relevant fields, and whose work would benefit significantly from the travel enabled by the Award. The Committee will consider nominations only—no direct applications will be enter- tained. Letters of nomination and supporting materials should be addressed to Dr. R. W. Kiger, Hunt Institute, Carnegie-Mellon University, Pittsburgh 15213; the deadline for their receipt is 1 May 1983.

ERRATUM

Madrono 29(3):217 has an error. The family given for Cenchrus incertus should be Poaceae instead of Cyperaceae. I thank Duncan Porter for bringing this to my atten- tion.—Ed.

66 MADRONO [Vol. 30

REVIEWS

Genera of the Western Plants. By WADE T. BATSON. 207 p. Published by the author, 1120 Blake Dr., Cayce, South Carolina 29033. $8.50. (20% discount to bookstores and libraries.)

This is a useful basic guide to the genera of ferns and seed plants of North America west of the 98th meridian and north of Mexico. Also included are a few of the commoner ornamentals of the region. It is clearly aimed at students and amateurs with some familiarity with arcane taxonomese, but plant geographers can also profit from a quick learning of what genera occur west of the 98th meridian, a boundary perhaps no more arbitrary than the Continental Divide. A great deal of information is packed into this pocket-sized volume.

Despite this, the book has a number of serious drawbacks. I would suggest typing the genus names in italics (the book is produced from camera-ready copy) and omitting the synonyms, or at least using the designation “syn:” to avoid some confusion. I did not use any of the keys but they appear to be typical of this kind of work from a reading of several in families whose members are familiar to me. The key leads are not always parallel, and I suspect some will be hard to use, whereas others will work fine. Each brief genus description is accompanied by a tiny drawing of leaf, flower, or habit. Some of the drawings are too small to be of much value, others will be better than nothing.

Apacheria (Crossosomataceae) and Dedeckera (Polygonaceae) are missing, and For- sellesia is still included in Celastraceae. Mollugo, Paeonia, Menyanthes, and Sim- mondsia are now usually placed in separate families; Cephalanthera (Eburophyton), Ceratoides (Eurotia), Eremalche (Malvastrum), Geocaulon (Comandra), Swallenia (Ec- tosperma), and Tiquilia (Coldenia) are the widely accepted segregates or names used in preference over the names in parentheses (used in this book). Zauschneria has been submerged into Epilobium but is retained here. Missing from the families treated is Proteaceae, surely as worthy of appearance as Myoporaceae and Caricaceae. The range of Vitis should be CA—CO, rather than UT—CO. These are a selection of the 33 errors I encountered. I was dismayed by the number of typos and feel that because the book is intended for students, more effort should have been made to eliminte them. In the main text I found 51, and in the index alone, 85. Pieris (Ericaceae) has crept into the key for Cichorieae and replaced Picris. The student must use this guide with caution.— C. Davipson, Idaho Botanical Garden, P.O. Box 2140, Boise 83701.

A Field Guide to Mushrooms and their Relatives. By COURTENAY BOOTH and HAROLD H. BURDSALL, JR. 144 p., black-and-white drawings, over 400 color photographs. Van Nostrand Reinhold Co., New York, Cincinnati, Toronto, London, Melbourne. 1982. ISBN 0-442-23117-2 (cloth). $18.95. ISBN 0-442-23118-0 (paper).

Although this book was intended primarily for the northeastern and central United States, it includes many species that occur in the West. It is the only handbook providing color photographs of some of these species. For this reason, there will be many who will wish to add it to their libraries. The book was not intended as a guide for mycoph- agists. They should regard it as a supplementary volume because of the absence of many important anatomical details and information about mushroom poisons. In my opinion, the statement in the preface that the book was intended to permit quick iden- tification of species by amateurs is overly optimistic. The abundance of color illustrations and common names will appeal to many casual observers, however.

The book includes a very brief, simplified discussion about the nature of fungi and an explanation of scientific names. Simple words rather than scientific terms are used in a list of macroscopic characters used in identification (unfortunately the caption below the grouped and clumped habits were interchanged). The groups into which the fungi are divided are illustrated by simple line drawings. The photographs, which are ar-

1983] REVIEWS 67

ranged in the same order, are not numbered. The position of some photographs makes it difficult to determine the identity of the fungus illustrated. Although the color in some photographs is poor (for example, Coprinus atramentarius), an asset is the inclusion of various color variations of Armillariella mellea. Although there are many photographs of polypores, the use of currently accepted scientific names and absence of synonyms will confuse some readers. For each species there are brief comments about color, size, various surface features, habitat, and edibility. It would have been better to list both Pholiota aurivella and Agaricus sylvicola as “not recommended” and to point out that the gills of Chlorophyllum may remain white for a long period. The section on boletes is of limited usefulness in the West. A glossary and index are included; the latter contains a number of misspellings.—ISABELLE TAVARES, Department of Botany, University of California, Berkeley 94720.

ANNOUNCEMENTS

THE 1982 JESSE M. GREENMAN AWARD

The 1982 Jesse M. Greenman Award has been won by Walter S. Judd for his pub- lication “A monograph of Lyonia (Ericaceae)” (Jour. Arnold Arbor. 62:63—209; 315— 436. This monographic study is based on a Ph.D. dissertation from the Department of Biology, Harvard University.

The Greenman Award, a cash prize of $250, is presented each year by the Missouri Botanical Garden. It recognizes the paper judged best in vascular plant or bryophyte systematics based on a doctoral dissertation which was published during the previous year. Papers published during 1982 are now being considered for the 16th annual award, which will be presented in the summer of 1983. Reprints of such papers should be sent to: Greenman Award Committee, Department of Botany, Missouri Botanical Garden, P.O. Box 299, St. Louis, MO 63166-0299, U.S.A. In order to be considered for the 1983 award, reprints must be received by 1 July 1983.

WILDLAND SHRUB SYMPOSIUM

The second in a series of symposia dealing with the biology of wildland shrubs is announced by Brigham Young University. Entitled “The biology of Atriplex and related chenopods,” it will be held on 4-6 May 1983, in the Brigham Young University Con- ference Center, Provo, UT. An application and call for papers form can be obtained from Cooperative Extension Service, % Dr. Kendall L. Johnson, Utah State University, UMC 49, Logan, UT 84322.

PUBLICATION NOTE

Re-publication of Flora of the Mount Hamilton Range of California (1982) by Helen K. Sharsmith is most welcome. Originally published in American Midland Naturalist in 1945, this extremely useful local flora, covering a prominent area in the central Inner Coast Ranges, has long been out of print. Addition of an index that contains cross references to names as given in Munz, A California Flora and Supplement (1973) en- hances the value to users. The Santa Clara Valley Chapter of the California Native Plant Society is to be commended for making this Flora once again available. Copies may be obtained from: California Native Plant Society, SCVC-Book, 20531 Black Road, Los Gatos, CA 95030.

68

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CALIFORNIA BOTANICAL SOCIETY

MADRONO

VOLUME 30, NUMBER 2 APRIL 1983

Contents

A CLIFF BRAKE HYBRID, PELLAEA BRIDGESII X MUCRONATA, AND ITS SYSTEMATIC SIGNIFICANCE, Warren H. Wagner, Jr., Alan R. Smith, and Thomas R. Pray 69

A REVISION OF ABUTILON SECT. OLIGOCARPAE (MALVACEAE), INCLUDING A NEW SPECIES FROM

MEXxIco,

Joan E. Fryxell 84 NEw TAXA OF WESTERN AMERICAN ERYNGIUM

(UMBELLIFERAE),

M. Yusuf Sheikh 93

EURASIAN WEED INFESTATION IN WESTERN MONTANA IN RELATION TO VEGETATION AND DISTURBANCE, Frank Forcella and Stephen J. Harvey 102

CHEMOSYSTEMATIC AFFINITIES OF A CALIFORNIA

POPULATION OF ABIES LASIOCARPA,

Edward A. Cope 110 A NEw VARIETY OF PERITYLE STAUROPHYLLA (ASTERACEAE)

FROM NEW MExiIco,

Thomas K. Todsen 115 VEGETATION OF THE ALABAMA HILLS REGION, INYO

COUNTY, CALIFORNIA,

Vincent Yoder, Michael G. Barbour, Robert S. Boyd, and

Roy A. Woodward 118

NOTES AND NEWS

A MALE STERILE MorPH IN Lycium fremontii (SOLANACEAE) FROM BAJA CALIFORNIA SUR, A. J. Gilmartin 127

NOTEWORTHY COLLECTIONS

WEST AMERICAN JOURNAL OF BOTANY

NEw MExIco 126 CALIFORNIA 129 REVIEW a 131 ANNOUNCEMENTS 83, 101

PUBLISHED QUARTERLY BY THE CALIFORNIA BOTANICAL SOCIETY

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A CLIFF BRAKE HYBRID, PELLAEA BRIDGESII x MUCRONATA, AND ITS SYSTEMATIC SIGNIFICANCE

WARREN H. WAGNER, JR. Department of Botany, University of Michigan, Ann Arbor 48109

ALAN R. SMITH Department of Botany, University of California, Berkeley 94720

THOMAS R. PRAY Department of Biological Sciences, University of Southern California, Los Angeles 90007

ABSTRACT

The taxonomic position of Pellaea bridgesii has been questioned because of its dis- tinctive soriation and lack of strongly reflexed segment margin. In these characters, P. bridgesii differs from its presumed congeners only in degree. Furthermore, its peculiar glands appear no different from those of other pellaeas. The discovery of hybrids be- tween this species and P. mucronata var. mucronata, a “typical” member of the genus, suggests an unexpectedly close relationship between P. bridgesii and other species of Pellaea sect. Pellaea, particularly the P. mucronata group in western North America. This hybrid, here named P. x glaciogena, shows morphological intermediacy in nearly all characters between the putative parents, 58 univalents at meiosis, and mostly mal- formed spores or abortive sporangia. It is known from several localities at middle elevations in the central Sierra Nevada of California.

Studies of interspecific hybrids may yield clues to the relationships of their parents. In ferns if hybrids form at all this gives significant evidence of affinity between species. There are indications that inter- actions of strongly different parental characters may take various forms (Wagner 1960), and we may be able to obtain from hybrids valuable insights into morphogenetic processes. The plants to be described in this paper provide an excellent example of hybridization that involves plants of seemingly very different morphology. The presumed parents have been suspected by some on morphological grounds of belonging to different sections or even genera.

SYSTEMATICS

The problem of Pellaea bridgesit

Pellaea bridgesii Hooker has given rise to speculation concerning its taxonomic position. The problem of the relationships of this plant

MADRONO, Vol. 30, No. 2, pp. 69-83, 20 April 1983

70 MADRONO [Vol. 30

will be noted briefly, and then its cross with a more “normal” member of the genus will be described in detail.

This distinctive fern grows in exposed rocky places in the Sierra Nevada of California (Howell and Long 1970); disjunct populations occur in Oregon and Idaho (Hitchcock et al. 1969, Taylor 1970). Bot- anists generally have been uncertain about its precise generic relation- ships. Hooker (1858, p. 238), for example, wrote: “This is a very remarkable Fern, with much in the habit and in the nature of fruc- tification of Pellaea (Platyloma, J.Sm.) paradoxa, falcata, and rotun- difolia . . . and quite destitute of involucre. In short, as far as the sori are concerned, one can hardly see why it should not range with Gym- nogramme.” In her monograph of Pellaea sect. Pellaea, A. Tryon (1957) stated that “the position of Pellaea bridgesit ... remains a problem. I have excluded it on the basis of the conduplicate segments lacking reflexed margins, the short stalked sporangia which are borne on an elongated receptacle one quarter to one half the distance to the costa and which persist in a cup-like form after dehiscence. It resem- bles some species of Notholaena in the length of the receptacle and in the abundant waxy indument produced among the sporangia.” Cron- quist (in Hitchcock et al. 1969) commented further that “Pellaea bridgesii is transitional between Pellaea and Notholaena, and is anom- alous in either genus, without being sufficiently distinctive to warrant its erection as a monotype.”

Thus, P. bridgesit has remained more or less an enigma among North American adiantoid ferns. In particular the absence of the re- flexed margin so characteristic of Pellaea, the gymnogrammoid pattern of sori, and resemblances to members of the genus Notholaena have left authors undecided about its taxonomic affinities. In the course of our investigations on the hybrid cliff brake to be described below we have been able to arrive at a clearer conception of the homologies of P. bridgesii vis-a-vis Pellaea and to adduce strong evidence for its actual relationships.

The hybrid between P. bridgesit and P. mucronata

It is interesting to find morphological intermediates between P. bridgesi1 and an unquestioned member of Pellaea sect. Pellaea. For reasons to be given, we believe these intermediates are with little doubt of hybrid origin between P. bridgesii1 and P. mucronata. Because of the unusually wide morphological differences between the putative parents and also the apparent repeated formation of the hybrid, we choose to designate the intermediates by a hybrid binomial:

Pellaea < glaciogena Wagner, Pray & Smith, hybr. nov.

Planta inter P. bridgesii Hook. et P. mucronata (D. C. Eaton) D. C. Eaton quasi intermedia et verisimiliter ex hybridatione harum

1983] WAGNER ET AL.: CLIFF BRAKE HYBRID a

specierum orta, ab ambobus rhachidi parum sulcata differt, pinnis 1-pinnatis 2-8 paribus pinnularum, apicibus pinnularum angularibus vel parum mucronatis, venis tantum fortuito anastomosantibus, mar- gine segmentorum fertilium revoluto undulato vel dentato, et sporis abortivis.

Intermediate between P. bridgesii and P. mucronata, differing from both in the slightly grooved rachis (terete in P. bridgesii, strongly grooved in P. mucronata); pinnae 1-pinnate with 3-4 (2-8) pairs of pinnules per pinna (1-pinnate in P. bridgesii, 3-pinnate in most P. mucronata); pinnule tips angular to slightly mucronate (obtuse in P. bridgesii, strongly mucronate in P. mucronata); veins casually anas- tomosing with 0-1 union per segment (4—5 anastomoses in P. bridgesit, veins free in P. mucronata); fertile leaf margins revolute but with the lower epidermis well exposed (faintly or not at all revolute in P. bridgesii, strongly revolute in P. mucronata); segment margins un- dulate to toothed (entire in P. bridgesii, strongly toothed in P. mu- cronata); spores malformed (well-formed and globose in putative par- ents).

TypE: CA: Tuolumne Co.: south rim of Tuolumne Canyon, ca. 1 mi (1.6 km) n. of Mather, 5200 ft (1580 m), 5 Jun 1961, Pray 1860 (UC; isotype MICH).

PARATYPES: CA: Mariposa Co., Little Yosemite, Jun 1878, Bradley s.n. (UC—2 sheets); Yosemite National Park, along Hwy 41 midway between turnoff to Glacier Pt. and Wawona Tunnel, ca. 5500 ft (1670 m), 30 May 1981, Smith &14a, 814b (UC). Tulare Co.: Palisade Cr. near junction with King’s River, 22 Jul 1920, Perkins s.n. (USC); Sequoia Natl. Park, Tokapah Falls, dry stony slope, below bluff ca. Y4 mi (0.4 km) n. of base of falls, 7500 ft (2300 m), 28 Jul 1963, Kiefer 617a (MICH); near Dorset Cr., Sequoia Natl. Park, 26 Jun 1958, Rodin 6222 (UC); Kings Canyon Natl. Park, Mist Falls, South Fork of Kings River, ca. 6000 ft (1830 m), 20 Jun 1962, Pray 1903 (USC); along General’s Hwy, near summit ca. 5.5 mi (8.8 km) n. of Sequoia Park boundary, 7500 ft (2300 m), 21 Jun 1962, Pray 1904 (USC); Upper Tokapah Valley, near Tokapah Falls, n. slope of valley about VY, mi (0.4 km) w. of base of falls, 7500 ft (2300 m), 23 Jun 1965, Pray 3204-3206, 3208, 3209 (USC). Tuolumne Co.: Yosemite Natl. Park, ca. 1 mi (1.6 km) n. of Mather Ranger Station, on south rim of Tuolumne River Canyon, 5200 ft (1580 m), 1955-1959, 1961, Pray 1014, 1020, 1048, 1049, 1070, 1515-1518, 1520, 1521, 1852-1858, 1861-1864 (all USC).

Hybrids from the type locality were fairly common and were grow- ing with abundant P. mucronata var. mucronata (tripinnate form) in the most exposed areas; Pellaea bridgesii was common on more shel- tered, north-facing slopes.

Additional stations for P. Xglaciogena are also consistent with a hypothesis of hybridization. Both parents were found growing with

72 MADRONO [Vol. 30

Smith 814a and 814b: P. mucronata var. mucronata was abundant on exposed west-facing rocky slopes, P. bridgesii was common at the bases of overhanging boulders on north- and northwest-fac- ing slopes, and two plants (5 m apart) of P. X glaciogena grew at the crest of a small knoll within 5 m of both parents. Kiefer 617a was from a single large clump growing amid an extensive pop- ulation of P. mucronata. Pellaea bridgesit was growing nearby, about 6 m away. Fronds of all three entities from this locality are il- lustrated in Fig. 1. Later collections by Pray (3204 to 3206, 3208, 3209) from this same locality indicate that the hybrids were associated with P. mucronata var. mucronata and that P. bridgesii was growing nearby. At this locality, Pray observed P. mucronata growing only on the warmer south-facing slope, whereas P. bridgesii was on the cooler north-facing side of the valley. Pray 1903 was found growing with P. mucronata var. mucronata, whereas Pray 1904 was associated with P. bridgesit.

All localities are granitic ones and were formerly glaciated; the ex- posed rocky areas thus allow the two parents to occur very near one another, rather than being elevationally separate, as is usually the case. The known localities for the hybrid form a north-south line a little over 170 km in extent at mid-elevations on the west side of the central Sierra Nevada. At these sites, topographic and climatic con- ditions are such that the truly montane P. bridgesii does come in close contact with the hot-lowland P. mucronata. In the Sierra, P. bridgesii occurs mostly between 1800 and 3000 m from Plumas to Tulare Coun- ty, except in the vicinity of Yosemite National Park, where it is re- corded as low as 1215 m (Howell and Long 1970). Throughout most of its range, P. mucronata var. mucronata is found below 1200 m, except in the central and southern Sierra Nevada where it extends in elevation up to 2300 m (Howell and Long 1970). Thus, the putative parent are sympatric only from Tuolumne to Tulare County at el- evations between 1200 and 2300 m.

The only other species of Pellaea known from the Sierra Nevada are P. brachyptera (Moore) Baker, which occurs only as far south as Placer County (Howell and Long 1970); P. breweri D. C. Eaton, which is found generally above 2700 m in the central Sierra Nevada; and the more distantly related P. andromedifolia (Kaulf.) Fée, usually at elevations below 1200 m. Reports of P. brachyptera and P. wright- iana Hook. in the Yosemite region (Hall and Hall 1912) are probably based in part on P. Xglaciogena. Both species are bipinnate and in that respect are superficially similar to the hybrid. The closest stations for P. wrightiana, as it is now understood, are in Utah and Arizona (Wagner 1965, Pray 1967). Rodin’s (1960) illustration of P. mucronata var. californica (Lemmon) Munz & Johnston is based on Rodin 6222, which we identify as P. Xglaciogena.

1983] WAGNER ET AL.: CLIFF BRAKE HYBRID ie)

Fic. 1. Specimens of Pellaea, all from Califonia, Tulare Co., Tokapah Falls. B. Pellaea bridgesii, Kiefer 625 (MICH). G. Pellaea Xglaciogena, Kiefer 617a (MICH). M. Pellaea mucronata var. mucronata, Kiefer 617b (MICH).

Variation within P. mucronata is complex and still not completely understood, but the species comprises two more or less discrete vari- eties (A. Tryon 1957). At the type locality of P. <glaczogena only fully tripinnate forms of var. mucronata occur. At other localities (excluding Pray 1904), tripinnate and sometimes bipinnate forms of var. mu- cronata are found. These latter are distinct from var. californica, which is a more compact plant of generally higher elevations, in that the pinnules are well separated in a manner similar to the pinnules of the tripinnate forms of var. mucronata. Variety californica is not known from any of the localities where P. <Xglaciogena has been collected. In spite of minor variation within var. mucronata at the various locali- ties, the nature of the hybrid is much the same in all.

At the one place where we have found var. californica near P. bridgesi1, an entirely distinct intermediate was collected. This plant (Pray 1053, USC, Little Yosemite Valley, ca. 2150 m) is morpholog- ically much closer to P. bridgesii and has fewer, much larger segments than in P. Xglaciogena. The distinctiveness of this putative hybrid

74 MADRONO [Vol. 30

Fic. 2. Chromosomes of Pellaea xglaciogena, Smith 814a (UC). Bar scale repre- sents 30 wm.

suggests that sufficient genetic differences distinguish the varieties of P. mucronata that when the respective hybrids are formed with P. bridgesii they are morphologically distinct.

Chromosome counts for P. Xglactogena showing 58 univalents at meiotic metaphase were obtained from Smith 814a (Fig. 2). Numerous cells were examined and none showed evidence of chromosome pair- ing. Pellaea bridgesit was counted from this same locality and showed 29 bivalents at meiotic metaphase (Smith 816, UC); counts of this species from several additional localities, to be reported fully later (Smith, ms.), also showed 29 bivalents at meiosis. These represent the first counts for P. bridgesii and agree with the base number (x = 29) known for Pellaea. Pellaea mucronata has heretofore not been ex- amined cytologically (reports by Love et al. 1977, are errors for P. truncata), but counts showing 29 bivalents at meiosis have now been made on several populations (Smith, ms.).

Phenology of P. Xglaciogena and parents at one locality (Mariposa County, Smith §14a) is noteworthy. In late May 1981, in a drier than average year, nearly all plants of P. bridgesiz had fully expanded fronds on which most sporangia already had passed through melosis and some had mature spores. This same year’s fronds of P. mucronata var. mucronata were just beginning to emerge and uncoil, were still less than one-half of their mature height, and were probably premeiot- ic by 1-2 months. The two plants of P. Xglaciogena showed inter- mediate development, perhaps closer to that of P. bridgesiz, but with most fronds just beginning to undergo meiosis. The earlier develop- ment of P. bridgesii may reflect its adaptation to a shorter growing season at its usually higher montane elevations.

1983]

TABLE 1.

WAGNER ET AL.: CLIFF BRAKE HYBRID is

COMPARISON OF Pellaea bridgesii, P. mucronata VAR. mucronata, AND P.

x glaciogena. An asterisk indicates the most obvious macroscopic diagnostic characters.

P. bridgesit

P. Xglaciogena

P. mucronata

Rhizome scales

Scale tip margins *Rachis cross-sec- tion *Pinna cutting

Undivided distal pinna pairs Pinna margin

*Pinnule pairs per pinna Epidermis (lower)

*Segment tips

Vein anastomoses per pinna Individual seg-

ments with anas-

tomoses

*Young pinnae with

mature spores

*Mature fertile pin- nae (last year’s leaves)

* False indusium

*Indusial margin Spores

cells 22 (16-32) um wide, thin- walled

smooth or undulate

cylindrical undivided all

broad layer 1-cell thick

0

middle lamella not obscured, no secondary thick- enings

obtuse-rounded

4-5 (1-8)

all

conduplicate

flat, adaxial sur- face fully ex- posed

slightly to not at all reflexed

smooth to undulate

normal, 32.0 (30— 45) wm diam.

cells 25.5 (16-37) jum wide, thick- er-walled

+ toothed

narrowly grooved adaxially

1-divided 2-8 unmodified 3—4 (2-8)

irregular thicken- ings

angular to mucro- nate

2—3 (0-5)

one-third

flattened ventrally to conduplicate

margins revolute, but with lower epidermis well exposed

reflexed

undulate to toothed

malformed, rarely very large, 65 (52-76) um diam.

cells 31 (21-40) wm wide, thick- walled

toothed

widely grooved adaxially

commonly 2-divid- ed 1-3

unmodified 6—7 (4-15)

middle lamella ob- scured by sec- ondary thicken- ings

strongly mucronate

0

none

flattened ventrally

margins revolute and entirely cov- ering lower epi- dermis

reflexed

strongly toothed

normal, 34.4 (29- 42) wm diam.

Comparative information regarding the three plants involved in this study is summarized in Table 1 (most obvious gross features of inter- mediate and parents denoted by asterisk). These characters and a few others are here discussed in more detail.

Rhizome scales were removed from stem tips and petiole bases and soaked in KOH before mounting in diaphane. All drawings were made

76 MADRONO [Vol. 30

Yyy JY YU WY UY L jij Yj

Fic. 3. Fertile segments (cross-sections) and rhizome scales of pellaeas. B. Pellaea bridgesii. G. Pellaea Xglaciogena. M. Pellaea mucronata var. mucronata. Specimen data as in Fig. 1, except as indicated. Upper drawings: thick sections at spore maturation stage, dried specimens relaxed. Lower drawings: cells of scales (M, Collins 422, MICH).

using a Bausch and Lomb Microprojector. Scales of P. bridgesii differ in two respects from those of P. mucronata in having narrower cells (with thinner walls) and mostly smooth margins in the distal half (Fig. 3). Scales of P. mucronata have wider cells (with conspicuously thicker walls) and the scale tips are definitely toothed (Fig. 4). The scales of the hybrid are intermediate (Figs. 3, 4).

Rachis shapes of P. bridgesii and P. mucronata are sharply different in cross-section, especially in their distal halves. Those of the former are cylindrical or nearly so in outline; those of the latter are strongly flattened and have a wide groove on the adaxial surface. The midrib of P. Xglaciogena has only a shallow, narrow, less pronounced adaxial groove.

Pellaea bridgesii is well differentiated from P. mucronata in the segment tips: smoothly rounded and obtuse in the former and prom- inently mucronate in the latter (Fig. 5). The mucro in P. mucronata is a hardened, sharply pointed structure 0.2-1.0 mm long. In the hybrid, very few tips were observed that lacked mucros and practically all have at least some projection. However, none of the mucros in the

1983] WAGNER ET AL.: CLIFF BRAKE HYBRID Te

Fic. 4. Rhizome scales and epidermises of pellaeas. B. Pellaea bridgesii. G. Pellaea x glaciogena. M. Pellaea mucronata var. mucronata. Specimen data as in Fig. 1, except as indicated. Upper drawings: scales from rhizome apex. B,, Kiefer 625 (MICH); Bz, Hunnewell 7610 (MICH). M,, Collins 422 (MICH); M., Wiggins 2317 (MICH). Middle drawings: upper epidermises. Lower drawings: lower epidermises.

intermediate are longer than 0.4 mm. Segment margins of P. bridgesii show a definite whitish border 1—4 cells wide and 1 cell thick (indicated by pale dotted line in Fig. 5). This margin is absent in P. mucronata and apparently in the intermediate.

Pellaea is generally regarded as a free-veined genus, but in a few species anastomoses are in fact more or less common. Long ago, Eaton . (1879) noticed in P. bridgesii that “Here and there the veinlets are seen to anastomose angularly, especially near the midvein... .” Ap- proximately a dozen segments each of the three taxa involved were cleared and examined in detail: all of those of P. bridgesii revealed anastomoses, but none of P. mucronata did (Fig. 5). In the interme- diate some segments have vein anastomoses and others do not. The average number of vein conjunctions in segments of P. bridgesii was 4.4 (1-8), in the presumed hybrid 0.3 (0-1), and in P. mucronata none. The venation pattern may be described as free with incipient intra- segmental anastomoses, discal and mainly marginal, and without in- cluded veinlets (terms from Wagner 1979). Venation differences clearly distinguish specimens of the hybrid from immature or bipinnate spec- imens of var. mucronata and convincingly show the participation of P. bridgesii in the hybridization. The only other dark-stiped Pellaea with foliar vein anastomoses is P. ternifolia, which occurs in Texas

78 MADRONO [Vol. 30

Fic. 5. Segment tips and venation of pellaeas. B. Pellaea bridgesii. G. Pellaea x glaciogena. M. Pellaea mucronata var. mucronata. Specimen data as in Fig. 1. Shad- ed drawings: segment tips shown in dried state, the lowest one in each group at spore maturation stage, the upper ones from previous year’s fronds. Unshaded drawings: cleared segments showing venation patterns.

and perhaps Arizona southward. Figures for the hybrid in Table 1 express the total average number of anastomoses in whole pinnae, so as to be comparable to figures for P. bridgesiz. Segments illustrating venation (Fig. 5) were artificially flattened; in life they are often con- duplicate, at least those of fertile segments.

Cross-sections of the segments show few anatomical differences among the putative parents and hybrid. Upper and lower epidermises are well marked from the mesophyll, and the outer paradermal walls of each are only slightly thicker than the inner walls. Palisade cells are tightly packed, roughly oval-oblong, and they occur in 4—6 layers to make up about two-thirds (one-half to three-fourths) of the meso- phyll thickness. Spongy parenchyma is thus developed only in a rather narrow stratum on the abaxial side. The veins, which pass through the spongy cells, are thus quite close to the abaxial epidermis. The only striking difference involves the anticlinal walls of the epidermal cells. In P. mucronata, the entire pattern of the middle lamella (lower epidermis) is obscured by presumed secondary layers of extraordinary thickness (Fig. 4). In P. bridgesii, the situation is approximately av- erage for ferns in general. In the hybrid, the anticlinal epidermal walls are clearly intermediate, strongly but irregularly thickened but with layers not so massive as in P. mucronata.

Fertile pinnae of pellaeas tend to undergo changes in orientation

1983] WAGNER ET AL.: CLIFF BRAKE HYBRID 79

from the time of spore formation to spore discharge (or senescing fronds). Young fertile segments of P. bridgesii vary from more or less conduplicate and laterally flattened to rolled and tubelike; those of P. mucronata (relaxed from the dried condition with hot KOH) are not so deformed, except for the false indusia that are rolled inward (Fig. 3). In P. Xglaciogena we find both conditions (Fig. 3): some of the segments are not strongly deformed, others are nearly conduplicate. The previous year’s fronds (1962) that still remained on these same specimens show the final orientation of the mature segments, as seen in the dried condition (Fig. 5, uppermost shaded drawings). Dried specimens of P. bridgesii are fully open, and all parts are completely exposed. Those of P. Xglaciogena show much exposed lamina, but the false indusium is revolute. Those of P. mucronata become com- pletely involute, almost like bean pods. The false indusia from the two sides of the segments meet each other in an interlocking line; thus, none of the abaxial lamina is exposed except at the base and tip.

The false indusia of the hybrid are apparently more or less inter- mediate between the putative parents in their orientation, at least in the living condition. Sori of P. mucronata are completely covered by the reflexed margin, whereas in P. bridgesii the soral band is com- pletely exposed at maturity. In P. Xglaciogena, the indusium does not cover the sori completely. Furthermore, the contour of the margin is intermediate in the hybrid. In P. bridgesiz the indusial outline is straight or nearly so; in the hybrid it is undulate to shallowly toothed (Fig. 5); and in P. mucronata it is prominently toothed, with the teeth from opposing margins tending to fit together in a tightly interlocking sys- tem (not shown in Fig. 5).

Diaphane mounts of spores cleared in KOH show that the spores of P. bridgesit and P. mucronata are of the usual, nearly spherical, trilete type found in the genus. There are 64 spores or nearly that number per sporangium in each species. In the hybrid, the spores are usually malformed, reflecting the inability to complete normal meiosis. Formation of normal-appearing spores is, however, occasionally pos- sible under optimum conditions (Pray 1971). Observations by Pray at the Tuolumne River site from 1955 to 1961 usually showed only abort- ed sporangia and malformed spores. Collections made in 1961, ap- parently an unusually good year, showed some very large spores 52— 76 wm in diameter; these were capable of germination, gametophyte development, and sporophyte formation (Pray 1971, unpubl.) and per- haps represent unreduced “mitospores” of the kind described by Mor- zenti (1962).

DISCUSSION

The ferns treated (for example, by Christensen 1938) as “Gymno- grammeoideae” tend to fall into two categories based on soriation—

80 MADRONO | [Vol. 30

those that are strictly gymnogrammoid with sporangia borne abaxially along the veins (e.g., Pterozonium, Jamesonia, Eriosorus, Syngram- ma, Coniogramme, Anogramma, Pityrogramma, Gymnopteris, Bom- meria, Hemionitis); and those that are cheilanthoid, the sporangia borne along the tips of veins and forming “marginal” sori (e.g., Chez- lanthes, Notholaena, Pellaea, Doryopteris). Most of the latter cheilan- thoid types bear “false indusia,” which are more or less altered margins that fold over the sporangia, at least until time of spore maturity. Although this large assemblage falls readily into two categories, it is not at all certain that soriation per se defines a wholly natural division. Also, when examined in detail, these ferns prove to have various intermediate types of soriation. Coniogramme, for example, tends to have all the veins covered by sporangia, so that the entire abaxial surface of the pinna is “fertile.” In Pterozonium the sporangiferous area is only a band, and this is situated roughly between the middle and the margin of the segment. In three species of Bommeria, spo- rangia occur along the veins over much of the abaxial surface, while in a fourth species, B. ehrenbergiana, sporangia are more restricted to the margins and cover only a quarter to a third of the distance from the lamina margin to the costa of each ultimate segment (Haufler 1979). In the Old World, soriation patterns have caused great confu- sion in delimitation of the closely related genera Syngramma (gym- nogrammoid sori) and 7aenitis (sor! gymnogrammoid, or in marginal or inframarginal bands) (Holttum 1968, 1975).

There are also examples of obviously closely related species in this general circle of affinity in which the sori are more or less radically different. Pteris lidgatii differs from its obvious relatives (P. quad- riaurita group) in having discrete marginal sori rather than a contin- uous coenosorus (Wagner 1949). In California, Cheilanthes (or Aspi- dotis) californica and C. siliquosa show a striking contrast: sori of the former are solitary, separate units with 1-5 sporangia; and of the latter are continuous, band-like clusters (with hundreds of sporangia) that run nearly the length of the segment. The systematic relationship be- tween this pair of ferns is very close, as judged by the totality of resemblances. Also, they are connected by an intermediate, C. car- lotta-halliae, of allopolyploid origin (Wagner and Gilbert 1957, Smith 1975). In general, it is becoming increasingly apparent that soriation by itself may be an unreliable character if used solely to the exclusion of other taxonomic information.

The sorus of Pellaea bridgesii seems actually to be different only in degree from more typical species of its genus. In all pellaeas, including P. bridgesii, there is a marginal “flap” or false indusium that extends beyond the veinlet terminations. Stomata occur on the abaxial surface of this flap. Also, in all species, including P. bridgesii, the sorus is not a line but actually a band, many sporangia wide. From a strictly homological standpoint, Hooker (1858) was incorrect in saying that an

1983] WAGNER ET AL.: CLIFF BRAKE HYBRID 81

“involucre” (=indusium) is absent in P. bridgesiz as contrasted to other pellaeas. Although P. bridgesiz may be the only species in which the indusium is not reflexed, there are intermediate forms (as mentioned by Hooker himself). For example, P. atropurpurea has the margins reflexed over the sporangia in young sori, but the margins become completely open at maturity, fully exposing a broad band of sporangia. The most extreme opposite condition in the genus is illustrated by such species as P. mucronata (D. C. Eaton) D. C. Eaton in which the false indusium remains reflexed and covers the sorus at all times. The hybrid is of special interest for combining characters of species at opposite ends of the morphological spectrum in Pellaea as regards soriation.

One of the characters used by A. Tryon (1957) to exclude P. bridgesit from Pellaea sect. Pellaea was the possession of short-stalked sporangia; the stalk cells are approximately as long as wide, unlike many members of this section that have long stalks with stalk cells many times longer than wide. However, as she noted, P. mucronata is one of the species of this section that does possess short stalks. Thus the length of the sporangial stalk does not constitute a barrier for including P. bridgesii in sect. Pellaea.

The problem of the taxonomic placement of Pellaea bridgesii was exacerbated by the presence of glands among the sporangia. Secretory trichomes are widespread among gymnogrammoid and cheilanthoid ferns and are found in such well known farinose genera as Pityro- gramma and Notholaena. Most authors have failed to notice that such glands also occur in sori of certain species of Pellaea. Eaton (1879, p. 329) wrote that “A thing which has escaped notice hitherto is the presence on the back of the frond [of P. bridgesiz], especially between the lines of sporangia, of a little of the same ceraceous powder which is characteristic of the section Cincinalis of Notholaena, and of certain species of Cheilanthes and Gymnogramme. Indeed the very scantily reflexed involucre would seem to indicate that the plant would be quite as well placed in Notholaena as in Pellaea, a genus in which, I believe, no other species with farinaceous fronds have been placed.” However, Eaton overlooked these trichomes in other species of unquestioned Pellaea, i.e., P. mucronata, P. brachyptera, P. truncata, P. wright- tana, and P. ternifolia (A. Tryon 1957). Very likely, the glands usually have not been observed because they are buried as paraphyses in a narrower sorus covered by a reflexed margin (unlike the situation in P. bridgesii in which the broader sorus is completely exposed). Glands of P. bridgesii and other pellaeas apparently do not extend beyond the fertile area to the sterile surfaces of the lamina, and thus such glands are paraphyses in the narrow sense of the word.

The ability of P. bridgesiz and P. mucronata to hybridize repeatedly in nature suggests a close relationship between them. Fern species, in general, are not prone to hybridize across generic (or even subgeneric)

82 MADRONO [Vol. 30

lines, and those few intergeneric hybrids that are known are between very closely related genera about which there is disagreement over circumscription. Failure of synapsis and consequent sterility is the usual condition in interspecific fern hybrids, at least those that have not become stabilized by chromosome doubling (allopolyploidy) or apogamy. Thus, lack of pairing in P. Xglaciogena is expected.

In summary, doubts by Eaton (1879), A. Tryon (1957), Hitchcock et al. (1969), and others regarding placement of P. bridgesii can now, we believe, be dismissed. “Distinctions” between P. bridgesii and Pel- laea species proper involve only the aforementioned broadening of the soral band and lack or near lack of reflexing of the segment margin over the sorus. In all other characters, and in its geographical distri- bution, P. bridgesii is patently a member of the group that includes typical pellaeas (sect. Eupellaea Prantl, in Diels, 1902; sect. Pellaea of A. Tryon 1957), and should be so treated. More specifically, it is most closely related to the P. mucronata group, centered in California and Arizona and comprising the dark-stiped species with bicolored rhizome scales treated by A. Tryon (1957). It is best interpreted as the simplest member of a reduction series in frond complexity with P. mucronata var. mucronata as the alternate and most dissected extreme (Pray 1968).

ACKNOWLEDGMENTS

Research was supported by NSF Grant G-10846 to W. H. Wagner, Jr. The help of L. L. Kiefer, D. B. Lellinger, and Katherine Lim Chen is gratefully acknowledged. Frank A. Lang gave us some useful suggestions to improve the manuscript.

LITERATURE CITED

CHRISTENSEN, C. 1938. Filicinae. Jn F. Verdoorn, Manual of Pteridology, p. 522- 550. Martinus Nijhoff, The Hague.

DIELS, L. 1898. Polypodiaceae. Jn A. Engler and K. Prantl, eds., Die naturlichen Pflanzenfamilien, 1(4):139-339. Wilhelm Engelmann, Leipzig.

EATON, D. C. 1877-1879. The ferns of North America, Vol. 1. S. E. Cassino, Salem, MA.

HALL, H. M. and C. C. HALL. 1912. A Yosemite flora. Edler & Co., San Francisco.

HAUFLER, C. H. 1979. A biosystematic revision of Bommeria. J. Arnold Arbor. 60: 445-476.

HitTcHcock, C. L., A. CRONQUIST, M. OWNBEY, and J. W. THOMPSON. 1969. Vas- cular plants of the Pacific Northwest. Part 1: Vascular cryptogams, gymnosperms, and monocotyledons. Univ. Washington Press, Seattle.

Ho.ttum, R. E. 1968. A re-definition of the fern-genus 7Jaenitis Willd. Blumea 16: 87-95.

1975. A comparative account of the fern-genera Syngramma J. Sm. and Taenitis Willd., with discussion of their relationships to each other and to other genera. Kew Bull. 30:327-343.

HookErR, W.H. 1858. Species filicum. Vol. 2. Adiantum—Ceratopteris. William Pam- plin, London.

HowELL, J. T. and R. J. LoNG. 1970. The ferns and fern allies of the Sierra Nevada in California and Nevada. Four Seasons 3(3):1—18.

1983] WAGNER ET AL.: CLIFF BRAKE HYBRID 83

Love, A., D. LOVE, and R. E. G. PICHI SERMOLLI. 1977. Cytotaxonomical atlas of the Pteridophyta. J. Cramer, Vaduz.

MorZENTI, V. M. 1962. A first report of pseudomeiotic sporogenesis, a type of spore reproduction by which “sterile” ferns produce gametophytes. Amer. Fern J. 52:69— 78.

Pray, T. R. 1967. Notes on the distribution of American cheilanthoid ferns. Amer. Fern J. 57:52-58.

1968. The gametophytes of Pellaea section Pellaea: dark-stiped series. Phy-

tomorphology 18:113-143.

1971. The gametophytes of natural hybrids in the fern genus Pellaea. Amer. Fern J. 61:128—-136.

RopIN, R. J. 1960. Ferns of the Sierra. Yosemite Natural History Association. Crown Printing Co., Fresno, CA.

SMITH, A. R. 1975. The California species of Aspidotis. Madrono 23:15—24.

TayLor, T. M. C. 1970. Pacific Northwest ferns and their allies. Univ. Toronto Press, Toronto.

TRYON, A. F. 1957. A revision of the fern genus Pellaea sect. Pellaea. Ann. Missouri Bot. Gard. 44:125-193.

WAGNER, W. H., Jr. 1949. A reinterpretation of Schizostege lidgatii (Baker) Hillebr. Bull. Torrey Bot. Club 76:444-461.

1960. Irregular morphological development in hybrid ferns. Phytomorphology

12:87—100.

1965. Pellaea wrightiana in North Carolina and the question of its origin. J.

Elisha Mitchell Sci. Soc. 81:95-103.

1979. Reticulate veins in the systematics of modern ferns. Taxon 28:87—95. and E. F. GILBERT. 1957. An unusual new cheilanthoid fern from California. Amer. J. Bot. 44:738-743.

(Received 2 Nov 1981; revision accepted 19 Mar 1982.)

ANNOUNCEMENT

MEETING NOTICE

The Society for Economic Botany will hold its 24th annual meeting at Miami Uni- versity, Oxford, Ohio, June 13-15, 1983. This year’s symposium will deal with ETH- NOBOTANY IN THE NEOTROPICS. Information on the meeting can be obtained from Dr. Charles Heimsch, Botany, Miami University, Oxford, OH 45056 or Dr. Hardy Eshbaugh, Systematic Biology Program, National Science Foundation, Washington, DC 20550. Those wishing to contribute papers should contact Dr. Gregory Anderson, Biological Sciences Group, University of Connecticut, Storrs, CT 06268.

A REVISION OF ABUTILON SECT. OLIGOCARPAE (MALVACEAE), INCLUDING A NEW SPECIES FROM MEXICO

JOAN E. FRYXELL Department of Geology, University of North Carolina, Chapel Hill 27514

ABSTRACT

Abutilon subsect. Oligocarpae is raised to sectional status. It was originally established when Abutilon was a section of the genus Sida. Within this section, the identities of Abutilon pringlet and A. incanum have long been confused. Abutilon pringlei proves to be a synonym of A. imcanum, which grows in the Sonoran Desert and Hawaii. The species in Texas commonly known as A. incanum is properly named A. fruticosum, and does not extend into the Sonoran Desert. A key to the species of section Oligocarpae is given, along with full species descriptions. Abutilon mucronatum is described as new from western Mexico. It is distinctive because of its mucronate-tipped petals, glandular indumentum, and pungent odor.

Miller established the genus Abutilon in 1754. Later, Candolle, in the Prodromus treatment (1824), created the subsections Oligocarpae (with 5—8 carpels) and Polycarpae (with more than 8 carpels) under Sida section Abutilon. Sweet (1826) included Oligocarpae and Poly- carpae under Abutilon, which he, like all subsequent authors, treated as a genus. His treatment, however, left unclear the rank of these subgeneric categories. Only two species included in the Prodromus treatment (A. incanum and A. trisulcatum) now remain in section Oligocarpae. The other seventeen members of his subsection have been transferred to other genera or clearly have other affinities within Abu- tilon, e.g., A. umbellatum (L.) Sweet and A. giganteum (Jacq.) Presl. Abutilon incanum, A. trisulcatum, A. percaudatum, A. parvulum, A. malacum, and A. fruticosum form a distinct and cohesive group com- parable to other natural groupings within the genus, and merit rec- ognition as a section.

Abutilon Section Oligocarpae (A.DC.) J. Fryxell, comb. et stat. nov.—sSida sect. Abutilon subsect. Oligocarpae Candolle, Pro- dromus 1:467. 1824.—-TYPE (here designated): Abutilon trisul- catum (Jacq.) Urban.

Plants suffrutescent to herbaceous. Leaves cordate at base, acute to acuminate at apex, with regularly or irregularly serrated margins, canescent to tomentose throughout with fine stellate trichomes or mixed stellate and gladular trichomes. Fruits cylindro-truncate schizocarpic

MapRONO, Vol. 30, No. 2, pp. 84-92, 20 April 1983

1983] FRYXELL: REVISION OF ABUTILON 85

capsules with loculicidal dehiscence and 3 reniform seeds per carpel; carpels 5 (6—9 in A. fruticosum). Chromosome base number: x = 7.

The identities and ranks of two members of this section, Abutilon pringlei and A. incanum, have been confused for many years. The epithet zmcanum previously has been applied to a taxon with yellow to orange, spreading petals, occurring from Texas to Arizona, north- ern Mexico and Hawaii. The epithet pringlez has traditionally been applied to the taxon, with yellow or pink reflexed petals each with a maroon basal spot, whose range was considered to be from Arizona to Sinaloa and west into Baja California (Kearney and Peebles 1942, Correll and Johnston 1970). Kearney (1955) treated the two taxa as separate species in his key to Abutilon, but noted that “Abutilon prin- glei apparently intergrades with A. incanum and is probably only subspecifically distinct.” Felger and Lowe (1970) merged the two taxa, recognizing two subspecies, A. incanum subsp. incanum and A. in- canum subsp. pringlei, stating that “the differences for the most part involve . . . minor distinctions of color.” My studies have shown that there are several other characters, e.g., petal attitude, carpel number, and leaf shape, that differ and that distinguish these two taxa consis- tently (Fig. 1). Their separation at the specific level is warranted. In addition, field and herbarium observations revealed that their ranges do not, in fact, overlap. As noted above, the taxon known as Abutilon pringlei ranges from Arizona to Sinaloa west into Baja California, whereas the taxon that has been called A. imcanum is confined, in North America, to Texas and northeastern Mexico, with isolated pop- ulations in Oklahoma and Arkansas. In addition, this taxon is found in tropical and northern Africa, Arabia, southern Persia, Pakistan and northwestern India (Riedl 1976).

Link (1822) originally described Sida incana from the Sandwich (Hawaiian) Islands. Sweet transferred this species to Abutilon in 1826. Link did not include floral characters in his description, and the type specimen, housed in Berlin, has been destroyed. However, because there is only one taxon from this section occurring in the Hawaiian Islands, it is not difficult to determine what floral characters should be associated with the name. The taxon from western Mexico, pre- viously known as A. pringlei, has, for example, the reflexed petals with a basal spot and the trichome pattern identical to that of the Hawaiian taxon (A. incanum) and must be considered conspecific with it. Hochreutiner described A. pringlei from the Sierra Tucson in Ar- izona in 1902. Because Link’s epithet antedates Hochreutiner’s, the correct name for the Sonoran Desert and Hawaiian species is A. in- canum. The more