The Systematics of Lithospermum L. (Boraginaceae) and the Evolution of Heterostyly by James Isaac Cohen This thesis/dissertation document has been electronically approved by the following individuals: Davis,Jerrold I (Chairperson) Geber,Monica Ann (Minor Member) Luckow,Melissa A (Minor Member) Miller,James Spencer (Additional Member) Gandolfo Nixon,Maria Alejandra (Additional Member) Turgeon,E G Robert (Field Appointed Member Exam) THE SYSTEMATICS OF LITHOSPERMUM L. (BORAGINACEAE) AND THE EVOLUTION OF HETEROSTYLY A Dissertation Presented to the Faculty of the Graduate School of Cornell University In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy by James Isaac Cohen August 2010 © 2010 James Isaac Cohen 1 THE SYSTEMATICS OF LITHOSPERMUM L. (BORAGINACEAE) AND THE EVOLUTION OF HETEROSTYLY James Isaac Cohen, Ph.D. Cornell University 2010 Lithospermum L. (Boraginaceae) includes ca. 60 species. The genus has a nearly cosmopolitan distribution, being native to all continents except Australia and Antarctica. The center of diversity for the genus is Mexico and the southwestern United States, and approximately three-quarters of the species of Lithospermum are endemic to this region. Lithospermum and the tribe to which it is assigned, Lithospermeae, have been the subject of recent phylogenetic analyses, but these analyses have been limited in their scope. In order to examine critically the phylogenetics of Lithospermum and its relatives, three matrices, each consisting of 67 taxa, were constructed. The molecular matrix includes 10 chloroplast DNA regions, and the morphological matrix is composed of scores for 22 morphological characters. The combined matrix comprises the data from both of these matrices. Analyses of these matrices resolve Lithospermum as non-monophyletic, because members of other New World genera of Lithospermeae are found to be nested among species of Lithospermum. Because Lithospermum, as traditionally circumscribed, was resolved as non-monophyletic, the circumscription of the genus is expanded to include all species of New World Lithospermeae. Additionally, the phylogenetic distribution of various molecular and morphological characters was examined. One character, heterostyly, arose multiple times among the species of Lithospermum. The floral developmental patterns of three heterostylous and three homostylous species of Lithospermum were investigated. Although heterostyly may have originated independently in each of these three species, the floral developmental patterns of the long-style and short-style morphs of heterostylous species of Lithospermum are similar to those of homostylous relatives with approach and reverse herkogamous flowers, respectively. Despite similar gross floral developmental patterns, the developmental patterns of the stylar epidermal cells differ among the heterostylous species. In addition to phylogenetic and floral developmental studies, a revision of the species of Lithospermum of Mexico was undertaken, and species boundaries were reevaluated. Three new species are described from northern Mexico – L. chihuahuanum, L. kelloggiae, and L. tenerum – and each is known only from its type specimen. 2 BIOGRAPHICAL SKETCH James Isaac Cohen was born early in the morning on June 17, 1980. His early years were spent at Gan Hayeled Nursery School in Washington, DC. Afterwards, he attended Lafayette Elementary School, Alice Deal Junior High School, and Woodrow Wilson Senior High School, all part of the District of Columbia Public School system. During these formative years, James attended Camp Nebagamon, a boys’ camp in northwestern Wisconsin. As a camper, he spent much time in the Boundary Waters Canoe Area Wilderness in northeastern Minnesota. He truly enjoyed these outdoor experiences, and because of his love for the natural world, decided to study resource ecology and management at the School of Natural Resources and Environment at the University of Michigan, Ann Arbor. James was an excellent student in the Woody Plants course, a rite of passage at the school, and subsequently, he took other forest ecology courses. One of his graduate student instructors, John Syring, encouraged James to take a course in systematic botany. Because of his experiences in the Systematic Botany course, which was taught by William Anderson, James decided to learn more about the subject by reading books and botanizing with Dr. Anderson as well as taking courses with Robyn Burnham and Arnold Kluge. James graduated from the University of Michigan in 2002, and worked in various field botany and taxonomy positions throughout the USA. In order to continue to satisfy his interest in plant systematics, James applied, and was accepted, to Cornell University in 2004. Since his matriculation, he has learned a great deal on the subject of plant systematics, and has had wonderful experiences on the Ag Quad. Additionally, he has enjoyed his travels botanizing throughout the Americas. iii ACKNOWLEDGEMENTS Given that a doctoral dissertation is a long journey, it could not be accomplished without the help of others. Many people have contributed to my being able to complete my dissertation, and I owe them all a great deal of thanks. My advisor, Jerry Davis, has been incredibly helpful throughout all of the stages of my dissertation. I would like to think that after six years, Jerry’s attention to detail, precision, and thoughtfulness has rubbed off on me. Jerry has supported my ideas, provided guidance, and been a role model, and I hope to emulate him during my time on the other side of the lectern. The other members of my committee – Alejandra Gandolfo, Monica Geber, Melissa Luckow, Jim Miller, and Bob Turgeon – have always had their door open, and been willing to discuss various aspects of botany. In particular, the assistance and suppot that Alejandra, Melissa, and Jim have provided has been invaluable, and I will certainl not forget it. Other faculty members in the Hortorium and in the department of Plant Biology have provided me with guidance and treated me as I believe they would treat their own students. Jeff Doyle opened his lab group to me, and I learned a great deal concerning topics I otherwise would not have explored. Jim Reveal always has been willing to discuss topics related to taxonomy and nomenclature, and I appreciate his help. The students of the Hortorium have been wonderful companions. I believe that we have formed a tight-knit cohort that challenges and takes care of each other. Their friendship and intelligence have been a constant source of comfort. I have taken multiple collecting trips throughout North America, and many people have helped me during these trips. In 2005, Shannon Straub was a wonderful collecting partner, even though we only found a small number of species of Lithospermum. In 2007, during a trip to Mexico, Hilda Flores, Helga Ochoterrena, iv Paty Hernandez Ledesma, Fernando Alzate, and Socorro Gonzalez were invaluable friends to have in the field, and in 2008, during another trip to Mexico, Lucia Vazquez, Paty Hernandez Ledesma, and Janelle Burke made the collecting experience memorable. Finally, during 2009, Caroline Kellogg was a beautiful and helpful collecting assistant. In addition to trips to collect plant material, I also spent time at the New York Botanical Garden. It is through the generosity of Amy Litt and Dennis Stevenson that it was possible to visit the garden in the first place, and I am very appreciative for their help. While at the garden, Lisa Campbell, Damon Little, Larry Kelly, and Natalia Pabon Mora helped me with any questions I had regarding microscopy. These people, along with Fabian Michelangeli, Michael Sundue, and Donald McClelland, made me feel at home at NYBG, and that is always a nice feeling. Although I collected a great deal of plant material, various gardens and organizations sent me material or allowed me to collect on their property. These include the National Botanical Garden of Belgium, the Royal Botanical Garden at Kew, the Missouri Botanical Garden, USDA – GRIN, the National Park Service, the Chicago Botanical Garden, the South African National Biodiversity Institute, and the Cornell Plantations. Various organiziations and societies provided funding for my research: American Society of Plant Taxonomists, Molecular and Organismic Research in Plant History Cross-Disciplinary Training Grant, Cornell University Latin American Studies Program Travel Award, Cornell University Graduate School Research Travel Grant, Cornell University Sigma Xi Grant, Cornell University Mellon Funds, and the L. H. Bailey Hortorium Harold E. Moore Jr. Research Fund. Without assistance of these grants, it would have been very difficult to complete my dissertation. The funds provided are greatly appreciated. v I also have taught for eleven of my twelve semesters at Cornell. I would like to thank Karl Niklas, Tom Silva, Jerry Davis, Alejandra Gandolfo, Darlene Campbell, and Melissa Brechner for the opportunity to learn how to teach, and to work with them. Teaching at Cornell has been an interesting and fun experience, and I look forward to taking the lessons I have learned and applying them to future classrooms. Most importantly, I would like to thank my wife, Caroline Kellogg, for her support. She has gracefully put up with me during my time in graduate school, and has been willing to read anything I write. Caroline is a wonderful person, and without her, graduate school would have been a much more trying experience. I would be remiss if I also did