Systematics Section / ASPT
Cohen, Jim .
Lithospermum L. Systematics: Utilizing Multiple cpDNA Regions and Morphological Characters.
Lithospermum L. (Boraginaceae: Lithospermeae) consists of approximately 40 species in varied Old and New World habitats. The genus and related New World genera exhibit a variety of floral features and breeding systems. The purpose of this study is to elucidate phylogenetic relationships and examine character evolution among species of Lithospermum and related taxa, utilizing both DNA sequence data and morphological characters. Individual chloroplast DNA regions, both coding and non-coding, show variation among taxa, but parsimony-informative characters are few. Therefore, it has been necessary to sequence multiple chloroplast regions in order to obtain a well-resolved phylogeny. Various combinations of cpDNA regions suggest different relationships and provide different levels of resolution among New World Lithospermeae. Faucal appendages, pollen with a constricted equator, heterostyly, and a variety of corolla colors (including white, orange, and green-yellow) are derived character states in the New World members of the tribe; most of these derived states have evolved independently at least twice within the group. Current results suggest that two genera of New World Lithospermeae, Onosmodium and Macromeria, are nested within Lithospermum. The taxonomic implications and potential pathways of morphological evolution will be addressed.
Log in to add this item to your schedule
1 - Cornell University, Plant Biology, 228 Plant Science Building, Ithaca, New York, 14850, USA
Presentation Type: Oral Paper:Papers for Sections
Location: Lake Erie/Hilton
Date: Monday, July 9th, 2007
Time: 8:00 AM