Systematics Section / ASPT
Morden, Cliff , Montgomery, Rebecca A. .
Monophyletic origin and Adaptive Radiation in Hawaiian Chamaesyce (Euphorbiaceae) based on ITS and trnLF sequence variation.
Chamaesyce is a cosmopolitan genus of ca. 250 species. Although most species are low growing and often weedy, the Hawaiian complex (as currently circumscribed) constitutes 16 endemic species that have radiated from a single colonist into a spectacular assemblage. Species range from small shrubs to trees nearly 10 m tall with stems up to 30 cm in diameter. Habitats include coastal strand, dry shrubland, montane mesic and rain forests and range in elevation from sea level to 2000 m. All species manifest the C4 photosynthetic pathway, and are the only such plants to occur in tree form or in wet, understory habitats. Results based on molecular markers indicate that the Hawaiian species are monophyletic and represent a closely associated complex of species. C. celastroides, the most variable species in the islands, has eight recognized varieties. Our analysis suggests that taxonomic revisions are warranted and some varieties may deserve recognition at the specific rank. Data for other multivarietal species are not so conclusive.
1 - University of Hawaii, Center for Conservation Research and Training, Honolulu, Hawaii, 96822, USA
2 - University of Minnesota, Forest Resources, 1530 Cleveland Avenue N, Green Hall 115, St. Paul, Minnesota, 55108, USA
Presentation Type: Poster
Location: Special Event Center (Cliff Lodge)
Date: Tuesday, August 3rd, 2004
Time: 12:30 PM