Systematics Section / ASPT
Carrillo-Reyes, Pablo , Sosa, Victoria .
Phylogenetic relationships and position of Thompsonella (Crassulaceae).
THOMPSONELLA is a genus in the Crassulaceae of approximately eight species endemic to Mexico. Plants are herbaceous with succulent leaves arranged in rosettes, thyrsoid inflorescences, small flowers with reflexed petals with thin longitudinal red lines and apically elongated carpels. All species occur in tropical deciduous forests and xerophytic scrubs mostly in limestone. Molecular phylogenetic analyses have placed Thompsonella as part of the “Acre” clade, a highly diversified group formed mainly by American taxa. Monophyly and relationships of the Thompsonella species have not yet been determined. Forty six taxa from the “Acre” clade including all species of Thompsonella were considered in a molecular parsimony phylogenetic analysis, using ETS DNA sequences to determine if Thompsonella is a natural group. The results suggest that the genus is paraphyletic, because only one species, T. mixtecana was in a clade with species of Echeveria series Echeveria. Based on morphological characters a probable hybrid origin for T. mixtecana is discussed. The only well supported subclade within Thompsonella was formed by four species, T. minutiflora, T. spathulata, T. platyphylla and an undescribed species. They share their range of distribution in the dry areas where the upper areas of the Balsas and Papaloapan rivers come together.
Log in to add this item to your schedule
1 - Instituto De Ecología A.C., Postgrado, Apartado Postal 63, Xalapa, Veracruz, 91000, Mexico
2 - Instituto de Ecología, A. C., Biologia Evolutiva, Apartado Postal 63, Xalapa, Veracruz, 91000, Mexico
Presentation Type: Poster:Posters for Sections
Location: Auditorium/Bell Memorial Union
Date: Tuesday, August 1st, 2006
Time: 12:30 PM