This dissertation has been 64—6976 microfilmed exactly as received WELLS, James Ray, 1932— TAXONOMIC STUDIES OF THE GENUS POLYMNIA L. The Ohio State University, Ph.D., 1963 Botany University Microfilms, Inc., Ann Arbor, Michigan TAXONOMIC STUDIES OF THE GENUS POLYMNIA L. DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By JAMES RAY WELLS, B.S., M.S. The Ohio State University 1963 Approved by Adviser Department of Botany and Plant Pathology ACKNOWLEDGMENTS I wish to express my sincere gratitude to Dr. T. v Richard Fisher, my adviser, who suggested this problem and under whose guidance the work wan carried out. I am also grateful to Drs. Clara Weishaupt, J.W.A. Burley, C. E. Taft, and Glenn W. Blaydes for reading this dissertation and for offering helpful suggestions and criticisms. I am indebted to the curators of the several herbaria for making their material available. Permission to use Goode Base Maps (Copyright by the University of Chicago) for plotting plant distributions is gratefully acknowledged. This permission was granted through Goode Base Map Series, Department of Geography, The University of Chicago. My wife Jan, is due special recognition for her loyal support and cooperation throughout this endeavor. TABLE OF CONTENTS Page ACKNOWLEDGMENTS....................................... ii LIST OF T A B L E S ........................................ iv LIST OF ILLUSTRATIONS................................ v INTRODUCTION ........................................... 1 MORPHOLOGY ............................................. 3 GEOGRAPHIC DISTRIBUTION .............................. 5 ECONOMIC IMPORTANCE . .............................. 7 TAXONOMY ............................................... 8 KEY TO SPECIES AND VARIETIES.......................... 11 DESCRIPTION AND DISCUSSION OF T A X A .................... 15 EXPERIMENTAL TAXONOMIC INVESTIGATIONS ................ 131 LIST OF TAXA OF UNCERTAIN S T A T U S .........................156 LIST OF EXCLUDED SPECIES.................................160 DISTRIBUTION M A P S ....................................... 163 SUMMARY ................................................. 17^ BIBLIOGRAPHY ........................................... 175 AUTOBIOGRAPHY ........................................ 179 iii LIST OF TABLES Table Page 1 Polymnia uvedalia soil habitat data ............. 79 2 List of chromosome numbers of certain taxa of Polymnia.......... 13^ 3 Pollen stainability of taxa which occur naturally in the United States .............. 1^1 k Summary of interspecific hybridization attempts . 1^3 5 Summary of intravarietal hybridization attempts, selfings, and tests for ovulary abortion . 1^6 6 Crosses involving two plants of P. uvedalia var. uvedalia (collections 236 and 239^ from different ends of a large p o p u l a t i o n ......... 1^9 7 Summary of intraspecific hybridization attempts . 150 8 Crosses involving P. laevigata collection number 25^ ............ 153 iv LIST OF ILLUSTRATIONS Figure Page 1 Polymnia uvedalia (Holotype) ........... 10 2 Polymnia oaxacana (Isotype) .................. • 16 3 Polymnia laevigata (Isotype) ........ ...... 21 k Polymnia canadensis ............... 2k 5 Polymnia connata (Holotype) .................... k$ 6 Polymnia connata................................ ^-6 7 Polymnia .jelskii ( H o l o t y p e ).............. ^9 8 Polymnia .jelskii (Holotype F r a g m e n t s ) .......... 50 9 Polymnia siegesbeckia (Holotype) . ............ 52 10 Polymnia siegesbeckia .......................... 53 11 Polymnia riparia (Holotype) . ................ 55 12 Polymnia riparia ................................ 56 13 Polymnia maculata var. maculata ................ 62 l^f Polymnia uvedalia var. densipilis (Peduncle of Holotype) I T". .......................... 8l 15 Polymnia uvedalia var. floridana (Peduncle of Holotype) I 7~................................... 97 16 Polymnia uvedalia var. floridana ................ 98 17 Polymnia quichensis (Holotype) ........ ..... 10^ 18 Polymnia meridensis (Holotype) ..... ........ 107 19 Polymnia sonchifolia ............................. 110 20 Polymnia apus (Holotype)........................... 113 21 Polymnia apus (TIsotype) ....................... 11 ^ v LIST OF ILLUSTRATIONS— (Continued) Figure Page 22 Polymnia suffruticosa ............ 116 23 Polymnia pyramidalis ( H o l o t y p e ) .................. 119 24 Polymnia glabrata (Holotype) ............ 123 25 Polymnia parviceps (Holotype) ................ 125 26 Polymnia microcephala (Holotype) ..... ......... 127 27 Polymnia fruticosa ..................... 129 28 Polymnia laevigata pollen mother cell at diakinesis (Wells 255) ................ 135 29 Polymnia laevigata pollen mother cell at early metaphase (Wells 2 5 5 ) ........................ 136 30 Polymnia uvedalia var. uvedalia pollen mother cell at diakinesis (Wells 211) ............ 138 31 Polymnia uvedalia var. uvedalia pollen mother cell at diakinesis (Wells 2 1 1 ) .................. 139 32 Polymnia canadensis pollen mother cell at diakinesis (Wells 218) ...................140 33 Polymnia canadensis var. radiata (pollen parent) X Polymnia canadensis var. canadensis (ovule parent) hybrid ................................. ..... 151 34 Polymnia laevigata (pollen parent) X Polymnia canadensis var. canadensis (ovule parent) hybrid . 154 35 Polymnia bakeriana (Isotype)............ 157 36 Known distribution of Polymnia canadensis excluding Canada .................. 163 37 Known distribution of Polymnia uvedalia excluding Bermuda 164 38 Known distribution of Polymnia laevigata ...... 165 39 Known distribution of Polymnia oaxacana and Polymnia quichensis .......... 166 40 Known distribution of Polymnia apus and Polymnia maculata var. adenotricha ..................... 167 vi LIST OF ILLUSTRATIONS— (Continued) Figure Page 41 Known distribution of Polymnia maculata vars, maculata and glabricaulis .......... ..... 168 42 Known distribution of Polymnia riparia .......... 169 43 Known distribution of Polymnia glabrata. Polymnia parviceps, and Polymnia microcephala . 170 44 Known distribution of Polymnia pyramidalis and Polymnia connata .........................171 45 Known distribution of Polymnia siegesbeckia, Polymnia fruticosa, and Polymnia suffruticosa . 172 46 Known distribution of Polymnia sonchifolia and Polymnia meridensis......................173 vii INTRODUCTION The generic name Polymnia is derived from the Muse "Polyhymnia" who was one of the Greek goddesses of song and poetry. This Linnaean genus dates back to 1751* Heretofore, no known comprehensive study of the genus Polymnia has ever been carried out. This is an attempt directed toward producing a semblance of order and understanding in a poorly-understood genus. Earlier workers were not sufficiently aware of the limits of the genus Polymnia and partly for this reason it was often confused with other genera among which were: Adenostemma, Axiniphyllum, Berlandiera, Didelta, Guizotia, Melampodium, Montanoa, Rumfordia, Tetragonotheca, and Wedelia. E. L. Core (1955) and others have pointed out that a "revision" of a genus may be based only on studies of herbarium specimens from one continent or a smaller area whereas a "mono­ graph" is world-wide in scope and takes into account other disciplines such as: cytogenetics, anatomy, physiology, mor­ phology, paleobotany, and ecology. This study of the genus Polymnia does not readily fit into either of these two categories but has the characteristics of being world-wide in scope of coverage and based largely on studies of herbarium specimens. Also, where practicable, considerations are given to geography, cytology, ecology, and genetics. More thorough evolutionary considerations must await extensive travel and collections in the western hemisphere, particularly South America. Hybridization experiments along with cytological investigations will have to be carried out with all taxa. This, then, is an effort directed toward delimiting the taxa as they are now understood and at the same time laying the foundation for more experimental investigations and refinement of present concepts. A cytotaxonomist must know the currently valid name of the plants with which he is working. Although these names may not be truly representative of phylogenetic relationships, they will, at least, serve as a starting point from which various taxa may be combined or separated as experi­ mental evidence becomes known. Citations to herbarium specimens examined are made in accordance with abbreviations cited by Lanjouw and Stafleu (1959); Field Museum of Natural History (F), Gray Herbarium (GH), Indiana University (IND), Louisiana State University (LSU), Missouri Botanical Garden (MO), New York Botanical Garden (NY), University of North Carolina (NCU), Ohio State University (OS), Ohio University (OU), Philadelphia Academy of Science (PH), University of Tennessee (TENN), University of Texas (TEX), United States National Herbarium (US). MORPHOLOGY Polymnia species are for the most part perennials. Their root system is generally thought to be fibrous although no refer­ ence is known to me of the type of root system of the tree forms which grow in South America. In P. uvedalia, P. sonchifolia, and P. connata the underground parts are tuberous. The stems reach diameters up to 15-20 cm and attain heights of up to 12 meters. Stems may be terete, angular, or grooved. The stems may be glabrous or with glands and/or hairs. Sometimes the stems are purple-spotted