Lu-Irving, Patricia , Marx, Hannah , Olmstead, Richard .
Molecular systematics and character evolution in the Lantana-Lippia complex (Verbenaceae).
The Lantana-Lippia complex is a morphologically diverse group of approximately 400 named species, representing the largest radiation within the Verbenaceae s.s. It includes many aromatic species of ethnobotanical and economic significance, occurring in both North and South America, and also in Africa. Widespread morphological parallelism and intermediacy have hindered taxonomic efforts within this group. Evidence suggests that the Lantana-Lippia complex is a recently radiated lineage and previous phylogenetic studies have failed to achieve good species-level resolution. In order to infer the pattern of species diversification in the Lantana-Lippia complex and provide a contribution toward a broad, natural classification scheme, we have used rapidly-evolving DNA sequence markers from the chloroplast and nuclear genomes to resolve a species-level phylogeny for a representative sample of 85 species of the Lantana-Lippia group. The two principal genera of the Lantana-Lippia complex are traditionally distinguished by fruit type: Lantana is characterized by fleshy fruits, dispersed by birds, whereas in Lippia fruits are dry and seeds have no obvious adaptations for dispersal. Preliminary evidence suggests that neither genus is monophyletic and that fleshy fruits have evolved multiple times independently from dry-fruited ancestors. Members of the genus Aloysia form an ancestral grade to the rest of the Lantana-Lippia complex, along with members of smaller genera, suggesting that xerophytism may be the plesiomorphic condition in the group. The phylogeny illustrates the difficulty of achieving natural generic circumscriptions in this group using a rank-based classification scheme.
Log in to add this item to your schedule
1 - University of Washington, Department of Biology, Box 355325, Seattle, WA, 98195, USA
2 - University of Washington, Department of Biology and Burke Museum, Box 355325, Seattle, WA, 98195, USA
Presentation Type: Oral Paper:Papers for BSA Sections
Location: Rendezvous A/Snowbird Center
Date: Tuesday, July 28th, 2009
Time: 8:45 AM