GROSE, SUSAN O.* AND RICHARD G. OLMSTEAD. Department of Botany, University of Washington, WA 98195. - Phylogenetic Analysis of Crescentieae and Tabebuia s.l. (Bignoniaceae).
Bignoniaceae have been shown to be one of the four most abundant and
diverse families in several different neotropical ecosystems. Recent
phylogenetic studies based on cpDNA sequences have shown Bignoniaceae
to be monophyletic, and indicated that one of the largest tribes, the
Tecomeae is paraphyletic. In addition, one group of Tecomeae
including Tabebuia s.l. appears to be paraphyletic, having
given rise to tribe Crescentieae. We have expanded our molecular
phylogenetic studies based on ndhF to include increased
sampling of Tabebuia s.l. and Crescentieae to examine this
relationship further. This relationship, proposed by Alwyn Gentry, is
surprising because Tabebuia is characterized by dehiscent
fruits, non-cauliflorous inflorescences and bird or insect
pollination, while Crescentieae is distinguished by cauliflory,
indeshiscent fruits and bat pollination. Tabebuia s.l. has a
center of diversity in the Greater Antilles (mainly Cuba) with a
smaller proportion of species occurring in mainland Central and South
America while the Crescentieae have a primarily mainland Central
American distribution.
Key words: Bignoniaceae, cpDNA phylogeny, Crescentieae, Tabebuia s.l.