Systematics Section / ASPT
O'Leary, T. Ryan , Mort, Mark E. , Santos-Guerra, Arnoldo .
The Utility of cpDNA Sequences for Phylogenetic Inference in Aichryson (Crassulaceae): Implications for the Taxonomy and Biogeography of this Recently Diverge Lineage.
AICHRYSON is a genus of annual, biennial and perennial herbs (as well as two woody shrubs), comprising approximately 17 species. The genus is endemic to Macaronesia with 14 species occurring on the Canary Islands. Broad phylogenetic analyses have supported Aichryson as the monophyletic sister to a clade comprising two other Macaronesian genera, Monanthes and Aeonium. Focused analysis of Aichryson using 8 non-coding chloroplast DNA regions (7363 characters) and the nuclear ITS spacer region (589 characters) indicated relatively little divergence between taxa within all chloroplast sequences except for sequences of the psbA-trnH cpDNA spacer; relatively high divergence was found between the nuclear ITS sequences. Our analyses suggest that the extensive morphological variation noted among species of Aichryson was both recent and rapid. The extensive dispersal of species between islands and into similar habitats appears to have resulted in the convergence of several morphological features. This in turn, resulted in a high degree of taxonomic confusion, especially among the five subspecies in the A. pachycaulon complex. Biogeographic analyses suggest that Gran Canaria has been the source of at least two separate dispersals from the Canary Islands to Madeira.
Log in to add this item to your schedule
1 - University of Kansas, Ecology and Evolutionary Biology, c/o Mark Mort, 1200 Sunnyside Ave, Lawrence, Kansas, 66045, USA
2 - University of Kansas, Department of Ecology & Evolutionary Biology, Natural History Museum and Biodiversity Research Center, 1200 Sunnyside Avenue, Lawrence, Kansas, 66045-7534, USA
3 - Jardin de Aclimatacion de la Orotava, Calle Retama Numero 2, Puerto de la Cruz, Teneri, Canary Islands, E-38040, Spain
Presentation Type: Oral Paper:Papers for Sections
Date: Monday, July 31st, 2006
Time: 1:00 PM