Abstract Detail
Systematics Section / ASPT Vargas, Oscar [1], Madriñan, Santiago [1]. Monophyly and relationships of the Series of Diplostephium based on molecules and morphology: an adaptive radiation in the high Andes. Diplostephium is a genus of trees and shrubs with ca. 111 species. It is distributed along the Andes at high elevations from Venezuela to Chile, with two species also found in Costa Rica, and 12 in the Sierra Nevada de Santa Marta (Colombia), in what constitute the paramo and puna ecosystems. A phylogenetic analysis of the genus was performed based on molecules and morphology. The results show that the possible center of diversification was the Oriental Cordillera of the Andes in Colombia. In addition, mapping of morphological characters on the phylogeny shows a general pattern of reduction of the size of the whole plant, the leaves, and the number of capitula per inflorescence. After an initial radiation of the genus in the paramos of the Northern Andes, a second radiation may have occurred in the punas after crossing the dry paramos of Ecuador as evidenced by the monophyly of the Lavandulifolia, Rupestria and Anactinota series. The results reveal that some of the series proposed by Cuatrecasas are polyphyletic and/or paraphyletic, but forming a grade that that shows a sequential progression of morphological characters in strong agreement Cuatrecasas’ evolutionary hypothesis.
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An interactive key to Colombian species of Diplostephium
Laboratorio de Botanica y Sistematica
1 - Universidad de los Andes, Departamento de Ciencias Biologicas, Laboratorio de Botanica y Sistematica, Apartado Aereo 4976, Bogota, DC, 00001, Colombia
Keywords:
Diplostephium
Astereae
Asteraceae
phylogeny
molecular phylogenetics
morphology
paramo
puna.
Presentation Type: Poster:Posters for Sections
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P59046
Abstract ID:2334 | 