Brigham Young University BYU ScholarsArchive Theses and Dissertations 1969-05-01 A revision of the hedysarum boreale complex Terry Edwin Northstrom Brigham Young University - Provo Follow this and additional works at: https://scholarsarchive.byu.edu/etd BYU ScholarsArchive Citation Northstrom, Terry Edwin, "A revision of the hedysarum boreale complex" (1969). Theses and Dissertations. 8102. https://scholarsarchive.byu.edu/etd/8102 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]. THE GENUS HEDYSARUM IN NORTH AMERICA A Dissertation Presented to the Department of Botany Brigham Young University In Partial Fulfillment of the Requirement for the Degree Doctor of Philosophy by Terry Edwin Northstrom August 1974 This dissertation by Terry Edwin Northstrom, is accepted in its present form by the Department of Botany of Brigham Young University as satisfying the disserta- tion requirement for the degree of Doctor of Philosophy. August 16, 1974 Date ii ACKNOWLEDGEMENTS My cordial appreciation is expressed to Dr. Stanley L. Welsh, Brigham Young University, under whose supervision this study was carried out. Special thanks are given to Mrs. Kay Thorne for her help in preparing the illustration, Jim Allen for his help with the scanning electron microscopy and to the curators of the following herbaria who generously loaned their specimens: University of Alaska Herbarium (ALA); University of Arizona Herbarium (ARIZ); Brigham Young Uni- versity Herbarium (BRY); British Museum (BM); California Academy of Science Herbarium (CAS); National Museum of Can- ada (CAN); University of Colorado Museum (COLO); Dudley Herbarium of Stanford University (DS); Gray Herbarium of Harvard University (GH); Komarov Botanical Institute Herbar- ium (L); University of Michigan Herbarium (MICH); University of Montana Herbarium (MONT); Montana State University Her- barium (MONTU); New York Botanical Garden (NY); North Dakota State University Herbarium (NDA); University of Notre Dame Herbarium (ND); Bebb Herbarium of the University of Oklahoma (OKL); Oregon State University Herbarium (OSC); Herbarium of the Philadelphia Academy of Sciences (PH) ; Rocky Mountain Herbarium (RM); South Dakota State University Herbarium (SDU); United States Forest Service Herbarium (USFS); United States National Museum (US); University of Utah Herbarium iii (UT); Utah State University Herbarium (UTC); University of Washington Herbarium (WTU); Washington State University Herbarium (WS). iv TABLE OF CONTENTS Page ACKNOWLEDGEMENTS. .. .. .. .iii LIST OF TABLES. • • . • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • vi LIST OF FIGURES ••.•••••••.•••••.•.••••...•...•.•.•.•... vii INTRODUCTION. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 1 HISTORICAL ACCOUNT. .. .. .. 9 DISTRIBUTION. .. .. .. .. .. .. .. .. .. .. .. 11 TllE GROWTH CYCLE • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 12 GENERAL MORPHOLOGY. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 14 ANATOMY OF HEDY SAR UM. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 2 2 CHRO.MOSOMES. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 3 5 PH'YTOCHEMISTRY. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 52 TAXONOMY OF HEDYSARUM. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 7 4 INDEX TO EXSICCATAE. .. .. .. .. -160 BIBLIOGRA.PHY • ••••••••••••••••••••••••••••••••••••••••• • 17 5 v LIST OF TABLES Table Page 1. Taxa recognized for North America by vari- ous Authors since 1803 •••••••••••••••••••••• 4 2. Index of Hedysarum taxa described for North .Alnerica • ••••••••••••••••••••••••••••••• -. • • • • 6 3. Range and mean seed weights for Hedysarum taxa 21 4. Pollen grain measurements of Hedysarum taxa ••• 34 5. Chromosome reports for North American Hedy- sarUin taxa. • . 3 7 6. Phytochemical summary of Hedysarum taxa ••••••• 72 7. Quantitative variation of Hedysarum alpinum ••• 111 8. Character scores of Hedysarum alpinum ••••••••• 117 vi LIST OF FIGURES Figure Page 1. Flower of Hedysarum boreale ssp. mackenziei.. 38 2. Scatter diagram depicting the relationship of the width to length of the loment articles i~ H. alpinum, ~- sulphurescens and ~- ~~ cidentale. .. 3 9 3. Stem cross section of H. sulphurescens....... 40 4. Vascular bundle of H. occidentale............ 40 5. Xylem elements of H. boreale ssp. boreale var. rivulare ........ :-.......................... 41 6. Endodermis of H. occidentale................. 41 7. Leaf cross section of H. occidentale......... 42 8. Leaf cross section of H. boreale ssp. boreale 42 9. Cross section of petiole of H. boreale ssp. boreale var. rivulare ••••• 7................ 43 10. Cross section through receptacle of H. sul- phurescens • ••••••••••••••.•••••••• 7 .. :-:-:-. 44 11. Androecium cross section of H. boreale ssp. bore ale . ................... 7. • . 44 12. Ovule of H. boreale ssp. boreale............. 44 13. Cross section of young anther of H. boreale ssp. boreale •.••••••.•....•••.• 7........... 45 14. Mature anther wall of H. boreale ssp. boreale 45 15. Cross section of filament of ~· alpinum ••••••, 46 16. Cross section of corolla of H. alpinum....... 46 17. Cross section through calyx tube of li· ~- ~ ssp. boreale.......................... 47 vii Figure Page 18. Cross section through calyx tooth of H. boreale ssp. boreale ••••••••••••••• 7....... 47 19. Cross section of mature root of H. occiden- tale . .........................:- . 4 8 20. Root periderm of H. occidentale.............. 48 21. Pericarp cross section of H. alpinum......... 49 22. Seed cross section of H. alpinum............. 49 23. Pollen morphology of selected Hedysarum taxa. SO 24. Chromosomes of selected Hedysarum taxa....... Sl 25. Densitometer scan of H. boreale.............. 54 26. Densitometer scan of H. occidentale.......... SS 27. Habit of ~· boreale ssp. boreale var. rivu- lare. • . • . 7 8 28. Distribution of H. boreale ssp. boreale var. rivulare . .....:-. ... .. .. .. 80 29. Lament of ~· boreale ssp. boreale var. gremi- ale. • . 87 30. Habit of H. boreale ssp. boreale var. boreale 89 31. Habit of H. boreale ssp. mackenziei.......... 94 32. Polygonal graph comparing 8 characteristics of H. dasycarpum (U.S.S.R.) and H. boreale ssp. mackenziei (U.S.)..................... 97 33. Polygonal graph comparing 8 characteristics of Old and New World H. alpinum ............ 100 34. Ecological variation in H. bore·a1e ••••••••••• 102 35. Ecological variation in H. sulEhurescens ••••• 103 36. Ecological variation in H. occidentale ••••••• 104 37. Ecological variation in H. alEinum ••••••••••• lOS 38. Polygonal graph comparing 8 characteristics of H. hed~saroides (Europe) and H. al}2inum var. g:randiflo·rum (U.S.) ••••••••••••••••••• 108 viii INTRODUCTION Considering the fact that within the genus Hedysarum in North America some 46 epithets have been bestowed upon its various forms in American floras since 1803, {Table 1) Hedy- sarum lends itself well to a detailed morphological and bio- systematic study. In fact, not only are the systematics of Hedysarum taxa widely disputed, but their geographical dis- tribution, their ecological and physiological responses and their anatomy and morphology are poorly known. It has thus seemed worthwhile to undertake such a study. The genus Hedysarum in th~ family Leguminosae is a somewhat large genus of Old World origin which is largely north temperate and circumpolar in distribution. Estimates of the number of species within the genus vary widely.· B. A. Fedtschenko in his monograph of 1902 recognized 78 species for tbe world, but in a later work on the flora of the u. S. s. R. (1948), he recognized 88 species for the Soviet Union alone. At the other extreme, Willis (1973) estimates the total number of species at 150. After having critically ex- amined the North American.members of the genus, and assum- ing that the Old World entities have been treated equally, it appears that the total number of species does not exceed 100. In North America, Hedysarum taxa span an altitudinal 2 range of from sea level to 13,000 feet, a latitudinal range which extends from southern Arizona to Banks Island, and a longitudinal range extending from northwestern Alaska to Newfoundland. It occupies a vast variety of habitats rang- ing from gravel bars, sandy areas, roadsides and woodlands at low and moderate elevations, to alpine tundra and stony outcrops at high elevations or extreme northern latitudes. Thus, as one might expect, Hedysarum taxa exhibit a consid- erable degree of polymorphism which is usually expressed in the form of a gradient in morphological and physiological characteristics, the extremes of which often appear as dis- tinct entities occupying relatively large geographical areas. This appears to account for the numerous species, subspecies, and varieties as well as recombinations which have been de- scribed over the past 150 years (Table 2). Previous workers have dealt mainly with taxonomic considerations and little work has been done on the morphol- ogy, anatomy, and general biology of Hedysarum. This study is thus oriented from a somewhat biosystematic point of view. In order to correctly interpret taxonomically such a highly divergent