AN ABSTRACT OF THE THESIS OF J. Andrew Alexander for the degree of Doctor of Philosophy in Botany and Plant Pathology presented on November 7, 2007 . Title: A Taxonomic Revision of Astragalus mokiacensis and Allied Taxa within the Astragalus lentiginosus Complex of Section Diphysi . Abstract approved: _______________________________________________ Aaron I. Liston North America, with over 400 species of Astragalus (Fabaceae), is one of three major centers of diversity, all of which comprise the majority of the nearly 1750 species of Astragalus worldwide. One of the most diverse species, Astragalus lentiginosus of Section Diphysi , is a polymorphic complex of over 40 varieties, ranging from the West Coast to Texas and the Rocky Mountains. Palantia was a sectional name within the genus Tium used by Rydberg for taxa formerly reduced by Jones to varieties of A. lentiginosus. They share cylindrical pods that, unlike the rest of A. lentiginosus , do not become bladdery inflated upon maturity. The Palantia, in a modern interpretation, consists of A. mokiacensis and A. bryantii plus the other scarcely inflated varieties of A. lentiginosus , primarily A. lentiginosus var. maricopae , A. lentiginosus var. palans , A. lentiginosus var. ursinus , and A. lentiginosus var. wilsonii . Every major revision has delimited these taxa differently. A principal coordinates analysis of morphological data from herbarium specimens was used to determine the affinities between type specimens and extant populations of these taxa and to determine the degree of morphological similarity among these taxa. For the genetic analysis, highly polymorphic cpDNA microsatellites were selected due to their applicability to both genetic and phylogenetic questions across a wide range of taxonomic levels. Based on the results of the chloroplast haplotype and morphological datasets, the species, A. mokiacensis , A. bryantii , A. iodanthus and A. pseudiodanthus , are recognized as varieties of A. lentiginosus . The taxon recently recognized as A. lentiginosus var. trumbullensis is morphologically similar to the lectotype of Astragalus mokiacensis . Astragalus lentiginosus var. trumbullensis is herein recognized as a low-elevation minor variant and considered a synonym of A. lentiginosus var. mokiacensis. A taxonomic key and complete synonymy are included. Key words: Astragalus , Fabaceae, Edward Palmer, nomenclature, microsatellite, chloroplast, principal coordinates analysis, Utah, Arizona, Nevada A Taxonomic Revision of Astragalus mokiacensis and Allied Taxa within the Astragalus lentiginosus Complex of Section Diphysi . by J. Andrew Alexander A THESIS submitted to Oregon State University in partial fulfillment of the requirement for the degree of Doctor of Philosophy Presented November 7, 2007 Commencement June 2008 Doctor of Philosophy thesis of J. Andrew Alexander presented on November 7, 2007. APPROVED: _____________________________________________________ Major Professor, representing Botany and Plant Pathology _____________________________________________________ Chair of the Department of Botany and Plant Pathology _____________________________________________________ Dean of the Graduate School I understand that my thesis will become part of the permanent collection of Oregon State University libraries. My signature below authorizes release of my thesis to any reader upon request. ____________________________________________________________ J. Andrew Alexander, Author ACKNOWLEDGMENTS I would like to thank Dr. Wesley E. Niles. Without his influence and mentoring, I would not have the experience necessary to study an extremely complex taxon such as Astragalus lentiginosus . Additional thanks go to the late R. C. Barneby and the Barneby Fund for Research in Legume Systematics, which funded a month of research at the NY. I would also like to thank those who have provided encouragement, funding, assistance and information in the progress of my research: Aaron Liston and the staff of the OSU Herbarium; Brian Knaus for his assistance and training in the use of the molecular methods used in this study; Kathryn Birgy and the staff of the UNLV Herbarium; Gayle Marrs-Smith of the Las Vegas District BLM; Jerry Tiehm and the Northern Nevada Native Plant Society (and the NNNPS Small Grants Program); Emily Wood and the staff of the Gray Herbarium, and Lisa Decesare of the Library of the Gray Herbarium, Harvard University; Libby Powell of Lake Mead National Recreation Area; Denise Louie of Zion National Park; and the Moldenke Fund for Plant Systematics and the Harndman Fund at Oregon State University. My work was significantly influenced by S. L. Welsh and N. D. Atwood's revision and the extensive collections at the Welsh Herbarium; certainly, a greater understanding of the Astragalus lentiginosus complex would not be possible without their efforts. TABLE OF CONTENTS Page INTRODUCTION...............................................................................................1 CHAPTER 1: THE TAXONOMIC STATUS OF ASTRAGALUS MOKIACENSIS (FABACEAE), A SPECIES ENDEMIC TO THE SOUTHWESTERN UNITED STATES............................................33 CHAPTER 2: THE TAXONOMIC STATUS OF ASTRAGALUS BRYANTII , ASTRAGALUS LENTIGINOSUS VAR. MARICOPAE, ASTRAGALUS LENTIGINOSUS VAR. WILSONII , AND ASTRAGALUS LENTIGINOSUS VAR. URSINUS , FOUR TAXA ENDEMIC TO THE SOUTHWESTERN UNITED STATES........................56 CHAPTER 3: GENETIC DIFFERENTIATION BETWEEN POPULATIONS OF FIVE MEMBERS OF ASTRAGALUS SECTION DIPHYSI ENDEMIC TO THE INTERMOUNTAIN AND SOUTHWESTERN UNITED STATES............................................................91 CHAPTER 4: TAXONOMIC REVISION......................................................135 LITERATURE CITED......................................................................................219 APPENDIX 1.....................................................................................................233 LIST OF TABLES Table Page 1 A list of endemic species of Astragalus found in Welsh et al. (1994; 2003), Welsh 2007 and species classifications as found in works of Isely (1998) and Barneby (1964;1989).........................................................................21 2 The major taxonomic treatments of Astragalus mokiacensis from 1923-2005.............................................................40 3 List of 24 morphological characters and their abbreviations used in this study............................................................................43 4 Results of PCA of 12 variable morphological characters of 43 specimens of Astragalus mokiacensis ....................................44 5 Specific vouchers identified in the PCoA, cluster analysis, and parsimony figures and tables...............................................67 6 List of 24 characters and their abbreviations used in this study................................................................................................70 7 Results of PCoA of 21 variable morphological characters from 153 specimens of taxa in Astragalus Section Diphysi .......71 8 List of 12 morphological characters from 43 specimens of Astragalus mokiacensis and A. lentiginosus var. ursinus used in the PCoA analysis.....................................................................74 9 Results of PCoA of 11 variable morphological characters from 43 specimens of Astragalus mokiacensis and A. lentignosus var. ursinus .............................................................75 LIST OF TABLES (Continued) Table Page 10 Population name, herbarium voucher, location, and sample size data from the members of the Palantia and Astragalus Section Diphysi sampled in Arizona, Utah and Nevada......................................................................................99 11 Results of multiple populations genetic analysis of sampled members of the Palantia...............................................110 12 Haplotypes observed among the Palantia and sampled members of Section Diphysi .........................................................113 13 Haplotype frequencies among the Palantia and sampled members of Section Diphysi ........................................................114 14 Genetic diversity estimates for populations of sampled members of the Palantia and selected varieties of inflated A. lentiginosus .................................................................................115 15 Genetic diversity estimates from seven separate AMOVA analyses using five CpSSR markers, ccmp2, ccmp5, ccmp6, ccmp10 and trnT/L-839f...............................................................118 16 Specific vouchers identified in the distribution maps. ...........140 LIST OF FIGURES Figure Page 1 Pod texture character states in Astragalus adapted from Barneby (1964).................................................................................17 2 Pod dehiscence and persistence character states in Astragalus adapted from Barneby (1964).....................................18 3 Pod morphological character states in Astragalus adapted from Barneby (1964.).....................................................................19 4 Relationships among the sections of Astragalus, a phylogram adapted from Jones (1923).......................................24 5 Relationships among the sections of the Homaloboid Astragalus , a phylogram adapted from Barneby (1964)...........26 6 Relationships among the sections of the Piptoloboid Astragalus , a phylogram adapted from Barneby (1964)...........27 7 Intergradation between