Abstract a Taxonomic Reevaluation of Trifolium Variegatum Nutt
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ABSTRACT A TAXONOMIC REEVALUATION OF TRIFOLIUM VARIEGATUM NUTT. BASED ON MORPHOLOGY by Benjamin George Foster Trifolium variegatum Nutt. is a species of clover (Fabaceae) found in western North America. As a result of its geographic, habitat, and phenotypic diversity, the species has a complex taxonomic history. Hundreds of herbarium specimens of this and related species were studied in order to reevaluate the taxonomic status of the numerous morphotypes found within this species complex. Five segregates, T. appendiculatum, T. geminiflorum, T. polyodon, T. subsalinum, and T. ultramontanum, were considered to be potentially distinct from T. variegatum. Based on close investigation and the results of multivariate analyses, two segragates were accepted at the species level. The species recognized are Trifolium polyodon, a Monterey County, CA, endemic, T. appendiculatum, a large-flowered species found in cismontane California and southwestern Oregon, and T. variegatum, the most widespread and phenotypically diverse taxon. A TAXONOMIC REEVALUATION OF TRIFOLIUM VARIEGATUM NUTT. BASED ON MORPHOLOGY A Thesis Submitted to the Faculty of Miami University in partial fulfillment of the requirements for the degree of Master of Science Department of Biology by Benjamin G. Foster Miami University Oxford, Ohio 2015. Advisor________________________ (Michael A. Vincent) Reader_________________________ (R. James Hickey) Reader_________________________ (Richard C. Moore) Table of Contents Introduction ................................................................................................................................................ 1 Materials and Methods ............................................................................................................................. 6 Results and Discussion ............................................................................................................................. 10 “Trifolium geminiflorum” .......................................................................................................... 20 “Trifolium subsalinum” and “Trifolium ultramontanum” ......................................................... 28 Trifolium polyodon .................................................................................................................... 37 Trifolium appendiculatum ......................................................................................................... 45 Further Discussion ..................................................................................................................... 54 Taxonomic Treatment ............................................................................................................................. 55 References ................................................................................................................................................. 69 Appendices ................................................................................................................................................ 72 ii List of Tables Table 1. Published taxa in the Trifolium variegatum species complex (herbarium acronyms from Thiers, [continuously updated]) ...................................................................................................... 3 Table 2. List of taxa and synonyms accepted by McDermott in An Illustrated Key to the North American Species of Trifolium (1908) ............................................................................................. 4 Table 3. List of taxa and synonyms accepted by Zohary and Heller in The Genus Trifolium (1984) ......................................................................................................................................................... 5 Table 4. List of taxa and synonyms accepted by Isely in The Jepson Manual (1993) ..................... 6 Table 5. List of taxa and synonyms accepted by Vincent in The Jepson Manual (2012) ................ 6 Table 6. Characters and measurements used in this study for multivariate analyses ................... 8 Table 7. Character loadings on PC’s .............................................................................................. 12 Table 8. Proportion of specimens collected by month ................................................................. 46 iii List of Figures Figure 1. Drawings of laciniate organs .......................................................................................... 10 Figure 2. Principle components analysis projection of all T. variegatum s.l. OTU’s, colored according to potential groups. ...................................................................................................... 13 Figure 3. Principle components analysis projection of all T. variegatum s.l. OTU’s, colored according to accepted groups ....................................................................................................... 14 Figure 4. Principle components analysis 3-dimensional projection of all T. variegatum s.l. OTU’s, colored according to accepted groups ......................................................................................... 14 Figure 5. Cluster analysis using average linkage of all OTU’s, colored according to potential groups ........................................................................................................................................... 15 Figure 6. Cluster analysis using average linkage of all OTU’s, colored according to accepted groups ........................................................................................................................................... 16 Figure 7. Cluster analysis using Ward’s method of all OTU’s, colored according to potential groups ........................................................................................................................................... 17 Figure 8. Discriminant analysis of hypothetical groups ................................................................ 18 Figure 9. Discriminant analysis of accepted groups ..................................................................... 19 Figure 10. Discriminant analysis of recognized groups, with restricted characters ..................... 20 Figure 11. Distribution map of “T. geminiflorum” specimens ...................................................... 22 Figure 12. Beanplot of banner petal length .................................................................................. 22 Figure 13. Beanplot of stipule length ............................................................................................ 23 Figure 14. Beanplot of leaflet length ............................................................................................ 23 Figure 15. Beanplot of flower number ......................................................................................... 24 Figure 16. Specimen with two plants, one exhibiting “T. geminiflorum” morphology and the other “T. variegatum” morphology (Botti 154 (CAS)). ................................................................. 25 Figure 17. Specimen exhibiting “T. geminiflorum” morphology and “T. variegatum” morphology (Keck 1237 (CAS)). ......................................................................................................................... 26 Figure 18. “Trifolium geminiflorum” morph. ................................................................................ 27 Figure 19. “Trifolium geminiflorum” morph. ................................................................................ 27 Figure 20. “Trifolium subsalinum” morph (Williams 83-84-6 (RENO)). ........................................ 29 Figure 21. “Trifolium subsalinum” morph..................................................................................... 30 iv Figure 22. Distribution map of “T. subsalinum” specimens. ........................................................ 31 Figure 23. “Trifolium subsalinum” morphs compared. ................................................................. 31 Figure 24. Beanplot of the difference between banner petal length and calyx length ............... 32 Figure 25. Beanplot of banner petal length to calyx length ratio ................................................. 32 Figure 26. Beanplot of stem diameter .......................................................................................... 33 Figure 27. Specimen from Arizona exhibiting intermediate morphology between “T. subsalinum” and T. variegatum s.s. (Buegge 873 (ASU)) ............................................................. 34 Figure 28. Nevada specimen exhibiting intermediate morphology between “T. subsalinum” and T. variegatum s.s. (Kennedy 3056 (CAS)) ...................................................................................... 35 Figure 29. “Trifolium ultramontanum” morph ............................................................................. 36 Figure 30. “Trifolium ultramontanum” morph ............................................................................. 37 Figure 31. Map showing the distribution of specimens with pigmented or unpigmented calyx lobes within the Trifolium variegatum complex ........................................................................... 37 Figure 32. Distribution map of T. polyodon specimens ................................................................ 38 Figure 33. Drawing of dissected calyx of a specimen of T. polyodon (Heller 6759 (ISC)) ............. 39 Figure 34. Beanplot of