INFORMATION TO USERS This was produced from a copy of a document sent to us for microfilming. While the most advanced technological means to photograph and reproduce this document have been used, the quality is heavily dependent upon the quality of the material submitted. The following explanation of techniques is provided to help you understand markings or notations which may appear on this reproduction. 1. The sign or “target” for pages apparently lacking from the document photographed is “Missing Page(s)”. If it was possible to obtain the missing page(s) or section, they are spliced into the film along with adjacent pages. This may have necessitated cutting through an image and duplicating adjacent pages to assure you of complete continuity. 2. When an image on the film is obliterated with a round black mark it is an indication that the film inspector noticed either blurred copy because of movement during exposure, or duplicate copy. Unless we meant to delete i copyrighted materials that should not have been filmed, you will find a good image of the page in the adjacent frame. 3. When a map, drawing or chart, etc., is part of the material being photo­ graphed the photographer has followed a definite method in “sectioning” the material. It is customary to begin filming at the upper left hand comer of a large sheet and to continue from left to right in equal sections with small overlaps. If necessary, sectioning is continued again—beginning below the first row and continuing on until complete. 4. For any illustrations that cannot be reproduced satisfactorily by xerography, photographic prints can be purchased at additional cost and tipped into your xerographic copy. Requests can be made to our Dissertations Customer Services Department. 5. Some pages in any document may have indistinct print. In all cases we have filmed the best available copy. University M icrofilms International 300 N. ZEEB ROAD, ANN ARBOR, Ml 48106 18 BEDFORD ROW, LONDON WC1R 4EJ, ENGLAND 8100185 La D u k e , Jo h n C a r l SYSTEMATICS OF TITHONIA DESF. EX GMELIN (COMPOSITAE, HELIANTHEAE) The Ohio State University PH.D. 1980 University Microfilms International300 N. Zeeb Road, Ann Arbor, MI 48106 Copyright 1980 by La Duke, John Carl All Rights Reserved SYSTEMATICS OF TITHONIA DESF. EX GMELIN (COMPOSITAE, HELIANTHEAE) DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By John C, La Duke * * ic * * The Ohio State University 1980 Reading Committee: Approved By: Dr. Tod F. Stuessy Dr. Daniel J. Crawford Dr. Ronald L. Stuckey Dr. Gary L. Floyd Departm Botany ACKNOWLEDGMENTS Numerous people have assisted in the completion of this dissertation. Dr. Tod F. Stuessy, my major professor, is acknowledged for his encouragement and guidance in all phases of the study. Special thanks go to my committee Drs. Daniel J. Crawford, Ronald L. Stuckey, and Gary L. Floyd for their comments and criticisms of the dissertation. Field work for this study was supported by NSF grant DEB-7618763 which is gratefully acknowledged. Appreciation is extended to many graduate students who through their stimulating discussions contributed to the study. I also wish to thank the curators of the numerous herbaria who loaned specimens for this study (A, ARIZ, B, BM, BR, C, CAS, CGE, CM, CR, D S , DUKE, ENCB, F, FI, FSU, GH, GOET, LIV, M, MEXU, MICH, MO, MPU, NA, NY, OS, OXF, POM, RSA, S, SMU, TEX, U C , UPS, US, W, YU). Special thanks to my family for their support. VITA November 21, 1950 ........... Born - Jackson, Michigan 1973........................... B.S., Texas Tech University, Lubbock 1974-1975 .................... Teaching Assistant, Department of Biological Sciences, Texas Tech University, Lubbock 1975 ......................... M.S., Texas Tech University, Lubbock 1975-1979 .................... Graduate Teaching Associate, The Ohio State University, Columbus 1976 ......................... NSF - Doctoral Dissertation Research Grant 19 79 ......................... Ralph E. Alston Award, B.S.A. Annual Meeting 1979-1980 .................... Presidential Fellow, The Ohio State University, Columbus PUBLICATIONS La Duke, John C. and D.K. Northington. 1978. The systematics of Sphaeralcea coccinea (Nutt.) Rydberg. Southwestern Natur. 23: 651-660. Gardner, R.C. and J.C. La Duke. 1978. Phyletic and cladistic relationships in Lipochaeta DC (Compositae). Syst. Bot. 3: 197-207. La Duke, J.C. and D.J. Crawford. 1979. Character compatibil­ ity and phyletic relationships among several closely related species of Chenopodium of the western United States. Taxon 28: 307-314. FIELDS OF STUDY Major Field: Systematic Botany Studies in the phylogenetic relationships of Tithonia (Compositae). Professor Tod F. Stuessy. iv TABLE OF CONTENTS Page ACKNOWLEDGMENTS ....................................... a VITA..................................................... U i LIST OF TABLES......................................... v i LIST OF F I G U R E S ....................................... v a CHAPTER I. REVISION OF TITHONIA ......................... 1 Introduction .............................. 1 Taxonomic History ......................... 1 Generic and Subtribal Relationships ... 4 Cytology .................................. 9 Isolating Mechanisms .................... 13 Concepts of Species, Varieties, and S e c t i o n s ................................ 15 Numerical Taxonomy......................... 16 Phylogenetic Reconstruction .............. 34 Morphology and TaxonomicCriteria .... 46 Taxonomic Treatment ....................... 49 List of References......................... 139 II. FLAVONOID CHEMISTRY AND SYSTEMATICS OF TITHONIA (COMPOSITAE)......................... 146 A b s t r a c t .................................. 147 Materials and Methods .................... 150 R e s u l t s ..................................... 150 D i s c u s s i o n ................................ 163 APPENDIX A. Data matrix for the population study of the taxa of Tithonia........................... 178 v LIST OF TABLES TABLE CHAPTER I Page 1. Chromosome numbers in Tithonia ............ 10 2. Characters and character states of Tithonia used in the numerical study................ 18 3. Characters and character states used in the phylogenetic reconstruction of Tithonia. 38 4. Data matrix for the phylogenetic reconstruc­ tion of T i t h o n i a ........................... 39 CHAPTER II 1. Populations of Tithonia examined for flavonoids.................................. 151 2. Distribution of flavonoids in taxa of T i t h o n i a .................................. 154 3. Color reactions, Rf values and UV spectral data for selected flavonoids in Tithonia . 156 v i LIST OF FIGURES Figure Page CHAPTER I 1-4. Achenes of Viguiera and Tithonia ............ 7 1. V. excelsa 2. T . tubaeformis 3. T . fruticosa 4. T. calva var. calva 5-6. Pales of Viguiera and Tithonia .............. 7 5. V. rosei 6. T. calva var. calva 7. Phenogram of populations of Tithonia using UPGMA........................................... 23 8-9. First three principal component axes from analyzing populations of Tithonia u n r o t a t e d .................................... 26 10. Cluster analysis (UPGMA) of summarized data for taxa of T i t h o n i a .................. 29 11. Principal component analysis (unrotated) in three dimensions of summarized data for taxa of Tithonia .............................. 31 12-13. Cladograms of taxa of T i t h o n i a .............. 42 12. Based on character compatibility 13. Based on Wagner 78 14. Leaf outlines of T. rotundifolia............ 56 15. Disk corolla of T, rotundifolia ............ 56 16. Disk achene of T. rotundifolia.............. 56 v ii 17. Distribution of Tithonia rotundifolia in Mexico and Central America .................. 61 18. Leaf outlines of T. brachypappa.............. 67 19. Disk corolla of T. brachypappa.............. 67 20. Outermost disk achene of T. brachypappa. 67 21. Inner disk achene of T. brachypappa.......... 67 22. Distribution in Mexico and adjacent United States of Tithonia koelzii, T. brachypappa, T. calva var. calva, T. calva var. lancifolia, T. calva var. auriculata, T, fruticosa, and T. thurberi..................................... 70 23. Leaf of T. tubaeformis....................... 74 24. Disk corolla of T. tubaeformis.............. 74 25. Disk achene of T. tubaeformis .............. 74 26. Distribution of Tithonia tubaeformis in Mexico and Central America .................. 78 27. Leaf of T. thurberi .......................... 83 28. Disk corolla of T. thurberi................... 83 29. Disk achene of T. thurberi ................... 83 30. Leaf of T. koelzii ............................ 89 31. Disk corolla of T. koelzii ................... 89 32. Disk achene of T. koelzii..................... 89 33. Distribution of Tithonia pedunculata, T. diversifolia, and T. longiradiata Th Mexico and Central A m e r i c a ......................... 92 34. Leaf outlines of T. diversifolia............ 95 35. Disk corolla of T. diversifolia.............. 95 36. Disk achene of T. diversifolia.............. 95 37. Leaf of T. fruticosa .......................... 104 38. Disk corolla of T. fruticosa ................ 104 viii Disk achene of T, fruticosa .............. 104 Leaf of T. pedunculata.................... 109 Disk corolla of T. pedunculata........... 109 Disk achene of T, pedunculata ........... 109 Leaf, disk corolla, and disk achene of three varieties of Tithonia calva .... 116 43. Leaf, T. calva