Systematics Section / ASPT
Frasier, Cynthia , Struwe, Lena .
Strychnos exposed! The evolutionary past of a pantropical Loganiaceae genus using ITS.
Strychnos, a member of Loganiaceae, consists of an estimated 200 species that are pantropically distributed. These plants grow as small trees or lianas and have characteristic Melastomataceae-like leaves that have three to five major veins splitting at the base of the leaf. The four to five-merous flowers are small, gamopetalous, and often hairy. Strychnos has been used as a component of curare, a dart poison, and to treat numerous ailments from snakebites to gastrointestinal disorders. The pharmaceutical properties of this genus have been linked to alkaloids, such as the well-known toxin strychnine, and iridoids. Past work on Strychnos has been focused primarily on morphology, which has resulted in the division into12 generic sections. Sequences of the internal transcribed spacer (ITS) regions of the nuclear ribosomal DNA are being analyzed to investigate the phylogenetic relationships within Strychnos and to closely related Loganiaceae genera, e.g. Neuburgia and Gardneria. Parsimony analysis of preliminary data suggests that Strychnos is a monophyletic genus, but most of the 12 sections are not. The Asian endemic, Gardneria, has been placed as the sister genus and biogeographic patterns are becoming evident. Preliminary results point to subclades largely corresponding to continental distribution, and possible biogeographic hypotheses and age estimates will be discussed.
1 - Rutgers University, Ecology, Evolution, & Natural Resources, 14 College Farm Rd, New Brunswick, New Jersey, 08901, USA
2 - Rutgers University, Plant Biology and Pathology, Foran Hall, 59 Dudley Road, New Brunswick, New Jersey, 08901, USA
Presentation Type: Paper
Location: Cottonwood A (Snowbird Center)
Date: Monday, August 2nd, 2004
Time: 2:30 PM