Leaf architecture of Hamelieae (Rubiaceae)
Por:
Martínez-Cabrera D., Terrazas T., Ochoterena H.
Publicada:
1 ene 2007
Resumen:
The tribe Hamelieae sensu ROBBRECHT comprises seven genera, and is traditionally placed in subfamily Rubioideae. Molecular data, however, places Hamelieae within Cinchonoideae. In this study, leaf architecture characters were examined in order to provide further evidence for the circumscription of Hamelieae and discuss its placement in the proposed subfamilies. Leaves from 34 species belonging to six genera of the Hamelieae, plus Syringantha and representative species of Psychotrieae (Rubioideae), Cinchoneae (Cinchonoideeae) and Gardenieae (Ixoroideae) were studied in order to describe and compare their leaf architecture. The results showed that there are macromorphological characters shared by members of Hamelieae. The venation of Hamelieae is brochidodromous, as in the other sampled taxa, except Bouvardia, which has actinodromous venation and Randia with eucamptodromous-brochidodromous venation. In Hamelieae and Psychotrieae, marginal ultimate venation forms a fimbrial vein and raphides are present in the mesophyll, while in representatives of Cinchoneae and Gardenieae, marginal ultimate venation is incomplete and raphides are absent. Syringantha is distinguished by its narrow elliptical to lanceolate lamina, but shares several attributes with Hamelia and Hoffmannia. These attributes support the proposal to include Syringantha in Hamelieae. The results neither resolve the placement of Hamelieae in Rubioideae or Cinchonoideae. However, our current phylogenetic understanding of the family, placing this tribe in a clade within Cinchonoideae, suggests that raphides arised more than once independently, thus raphides should not be a taxonomic marker to define the Rubioideae. © 2007 Wiley-VCH Verlag GmbH & Co. KGaA.
Filiaciones:
Martínez-Cabrera D.:
Colegio de Postgraduados, Montecillo, Mexico
Programa de Botánica, Colegio de Postgraduados, Montecillo, Estado de México 56230, Mexico
Terrazas T.:
Universidad Nacional Autónoma de México, Instituto de Biología, Departamento de Botánica
Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de México, Apdo. Postal 70-633, D.F. 04510, México, Mexico
Ochoterena H.:
Universidad Nacional Autónoma de México, Instituto de Biología, Departamento de Botánica
Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de México, Apdo. Postal 70-633, D.F. 04510, México, Mexico
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