Brigham Young University BYU ScholarsArchive Theses and Dissertations 1965-08-01 Revision of gilia (polemoniaceae) section gilmania M. Eileen Matthews Brigham Young University - Provo Follow this and additional works at: https://scholarsarchive.byu.edu/etd BYU ScholarsArchive Citation Matthews, M. Eileen, "Revision of gilia (polemoniaceae) section gilmania" (1965). Theses and Dissertations. 8086. https://scholarsarchive.byu.edu/etd/8086 This Thesis is brought to you for free and open access by BYU ScholarsArchive. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of BYU ScholarsArchive. For more information, please contact [email protected], [email protected]. REVISIONOF GILIA (POLEMONIACEAE) SECTIONGILMANIA A Thesis Presented to the Department of Botany and Range Science Brigham Young University In Partial Fulfillment of the Requirements for the Degree Master of Science by M. Eileen Matthews May, 1971 • ACKNOWLEDGMENTS Grateful acknowledgment is made for the valuable suggestions and help given by the chairman of my advisory committee, Dr. Stanley L. Welsh, the chairman of the Department of Botany and Range Science, Dr. Dayna L. Stocks, and other members of my committee, Drs. Glen Moore and Dorald M. Allred. The author is also indebted to Daniel K. Johnson for photographic work, Dr. James L. Reveal and N. Duane Atwood for assis- tance in collection, and to Dr. Janice C. Beatley who made it possible for the author to pursue field work in the desert mountains of the United States Atomic Energy Commission's Nevada Test Site. Special is also given to the curntors of the hcrbaria who made spcciwcns available for study. Financial assistance was provided (in part) by a fellowship from the National Science Foundation (no. 999-00-8118). The Department of Botany and Range Science, Brigham Young University, supplied laboratory space, equipment, supplies, and financial support. iii TABLEOF CONTENTS Page ACKNOWLEDGMENTS iii LIST OF ILLUSTRATIONS V INTRODUCTION•...•. 1 Statement of Problem 1 Methods and Procedures 2 History of the Section 4 Infrageneric Relationships 10 General Morphology 32 Distribution and Ecology 43 Phylogeny 49 Cytology 51 TAXONOMY. 54 Key to the species of Gilia section Gilrnania 55 Gilia latifolia 55 Gilia ripleyi 63 SUMMARY 71 REFERENCES 72 APPENDIXA 78 APPENDIXB. 84 iv LIST OF ILLUSTRATIONS Figure Page 1. Holotype of Q. latifolia .. 5 2. Q. scopulorum collected from type locality 6 3. Isotype of G. stellata 7 4. Isotype of G. ripleyi 8 5. Leaf variation in G. latifolia 14 6. Leaf variation in G. la.tifolia 14 7. Leaf variation in G. ripleyi 15 8. Leaf variation in G. scopulorum 17 9. Leaf variation in G. stellata 17 10. Herbage pubescence in G. latifolia 19 11. Herbage pubescence in G. stellata 19 12. External flower form in G. latifolia and G. ripleyi 21 13. External flower form in G. scopulorum and G. stellata 21 14. Internal flower form in G. latifolia, G. ripleyi, Q. scopulorum, and Q. stellata 24 15. Capsule form in G. latifolia and Q. ripleyi 26 16. Capsule form in G. scopulorum and G. stellata 26 17. Seed form in G. latifolia, G. ripleyi, Q. scopulorum, and G. stellata . •.....• 28 18. Seed coat reaction to water in G. latifolia 30 19. Seed coat reaction to water in G. stellata. 30 20. Epidermal pattern in section Gilmania 34 21. Trichome form in section Gilmania 36 V Figure Page 22. Inflorescence in G. latifolia 38 23. Inflorescence in G. ripleyi .. 38 24. Petal venation in section Gilmania 40 25. Pollen form in section Gilmania ..• 42 26. Physiographic map of the southwestern United States . 45 27. Habitat of G. latifolia and~- ripleyi . 47 28. Pollen cell of G. ripleyi 52 29. G. latifolia 57 30. Southwestern United States. Distribution of G. latifolia 61 31. G. ripleyi 65 32. Southern Nevada and adjacent south~astern California. Distribution of G. ripleyi ...•........ 69 vi INTRODUCTION Statement of Problem The need for a revision of section Gilmania became apparent while the author was making routine identifications within the genus Gilia. Within Gilia, the taxa occupying the same general area have a strong tendency to exhibit parallel characteristics in response to common habit- at. This is especially true among the small-flowered species inhabiting the arid regions of the southwestern United States. In this region, gaps in variation between sympatric species are oftentimes less apparent than the gaps between related subspecies, making definition of infrageneric categories diffi~ilt. Subgenus Gilmania, as constituted by Mason and Grant (1948), although numbered among the small-flowered, arid region taxa, has been one of the most distinctive groups within the genus. The morphological and ecological relationships between its two members, G. latifolia and Gilia ripleyi are very close. A precursory study of contemporary keys and descriptions showed this closeness was no longer apparent beca•1se of the inclusion of additional species since 1956. With expansion of the group by Grant and Grant (1956a), two highly divergent groups were recognized within the section Gilmania (so reduced by Grant and Grant [1956a]). Later as a final modification, the original complex was completely obliterated (Grant, 1959) by its inclusion within the high- ly heterogeneous section Giliastrum, a group which combines a suffrutes- cent, broad-leaved, spiny, relict perennial with highly evolved, exceed- ingly delicate, linear-leaved annuals. This grouping alone warranted 2 closer analysis. Inasmuch as no explanation was given by Grant and Grant (1956a) or by Grant (1959) for the modifications other than "in view of the evident relationship. ." in the former publication, this study was undertaken to clarify the morphological, ecological, phylogenetic and cytological relationships of Q. latifolia and Q. ripleyi and to establish possible reasons behind the changes in classication. Methods and Procedures Data were obtained from herbarium specimens and from living plants in their natural ranges in Arizona, California, Nevada and Utah. Type specimens of both Q. latifolia and Q. ripleyi were examined. The measurement of large structures such as stem, leaf, and inflo- rescence was with a metric ruler. Plant height was measured from the base of the stem to the tip of the inflorescence. Leaf measurement was from the base of the petiole to the tip of the blade. Measurement of inflorescence was from the node of the lowest flowering branch to the apex of the highest flower. The measurement of small structures such as calyces, flowers, and capsules was by ocular micrometer fitted to the eyepiece of a dissecting microscope. When given, the extremes of dimen- sions were separated from the normal range by parentheses. All ratios are the quotients of the first measurement divided into the second. Paraffin sections (Gray, 1964) were used to make a series of slides from leaf, stem, root, flower and fruit. Pollen material was incidental on flower slides. Celluloidin peels (Sinclair, 1961) of the ab- and ad- axial surfaces of larger leaves were also made. Flowers and epidermal peels taken from pressed plant materials were first softened overnight in Pohlstoffe (Pohl, 1954) before they were mounted. Cytological material was collected during the summer of 1970 from 3 representative localities in California, Nevada, and Arizona. Chromo- some number determinations were made from pollen mother cells of flower buds (ca. 3.5 nun long from tip to base of calyx in Q. ripleyi, ca. 3.2 mm in G. latifolia) possessing anthers in a stage just prior to the in- itiation of chlorophyll production, the latter an indication of tetrad formation and overmaturity. Immediately upon collection, the huds·were fixed in a mixture of one part glacial acetic acid and three parts ab- solute alcohol and then refrigerated. After twenty-four hours in the above solution, the buds were stored in seventy per cent alcohol to pre- vent the brittleness associated with prolonged storage in fixative. The buds were then pre-stained for a variable period of time in acetocarmine dye, the anthers removed, and the pollen mother cells liberated. Stan- dard procedures .(Gray, 1964) were followed in mounting. A list of herbaria from which specimens were examined is given below. The abbreviations are, with a few exceptions, the standard ones given by Lanjouw and Staffleu (1964). ARIZ University of Arizona, Tucson ASC Northern Arizona University, Flagstaff BRY Brigham Young University, Provo (Utah) CAS California Academy of Sciences, San Francisco DIX Dixie Junior College, St. George (Utah) DS Dudley Herbarium, Stanford (California) GCT Grant Canyon National Monument Herbarium, Toroweap (Arizona) GH Gray Herbarium, Cambridge (Massachusetts) JEPS Jepson Herbarium, Berkeley (California) MO Missouri Botanical Garden, St. Louis NTS Atomic Energy Commission, Nevada Test Site, Mercury NY New York Botanical Garden, New York 4 ORE University of Oregon, Eugene POM Pomona College, Claremont (California) RM Rocky Mountain Herbarium, Laramie (Wyoming) RSA Rancho Santa Ana Botanic Garden, Claremont UC University of Ca1iforrtia, Berkeiey US United States National Museum, Washington, D. C. UT University of Utah, Salt Lake City lITC Intermountain Herbarium, Logan (Utah) WTU University of Washington, Seattle History of the Section Interpretation of the generic limits within the family Polemoni- aceae has had a long and difficult history. Gilia, the largest genus, has proved especially problematical to taxonomists. With the exception of Phlox and Polemonium, at some time or other, all of the herbaceous genera in the Polemoniaceae have been included in Gilia. The first species of section Gilmania to be described was Q. lati- folia. Collected by Dr. C. C. Parry at the "Valley of the Virgen [sic] near St. George," Utah in 1874, and described by Watson (1875) the fol- lowing year, the type specimen (Fig. 1) was included by its author in section Gilia (=Eugilia). Watson stated, however, that it was of "pecu- liar habit ... not approaching closely any of the other species." Three years later, Q. scopulorum (Fig. 2) was named by M.