Estudo taxonomico e analise cladistica do complexo Bifrenaria Lindl. (Maxillarieae, Orchidaceae)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2001

RESUMO

The Bifrenaria complex constitutes the South American genera Adipe (=Stenocoryne), Bifrenaria (sensu stricto), Cydoniorchis and Rudolfiella, which are characterized by four-angled, unifoliate pseudobulbs, plicate leaves, and by flowers bearing a conspicuous spur and a forked stipe. The aims of the present study were to investigate the monophyly of the Bifrenaria complex as well as the genera Adipe (=Stenocoryne), Bifrenaria, Cydoniorchis and Rudolfiella, based on morphology and DNA sequence data; to determine phylogenetic relationships within the Bifrenaria complex; and to reevaluate morphological characters traditionally used to delimit taxa. Sixteen species ITom the Bifrenaria complex and six related genera were sampled. Matrices were analysed using maximum parsimony. Separa te analyses of data partitions resulted in slight1y different topologies, therefore we combined alI the data sets. The results support the monophyly of the Bifrenaria complex, excluding Rudolfiella, which constitutes a monophyletic and distinct genus. Therefore we consider Bifrenaria a monophyletic genus comprising Adipe (=Stenocoryne), Cydoniorchis and Bifrenaria (sensu stricto). Within Bifrenaria, two clades are strongly supported: the Amazonian species clade and the southem Brazilian clade. The genus Adipe is a paraphyletic grade. Although the genus Cydoniorchis is monophyletic and presents many morphological synapomorphies, the acceptance of this genus would demand many nomenclatural changes. The results also suggest an Amazonian origin for Bifrenaria. In the second part of the study a taxonomic study for the genus Bifrenaria is presented. The main goals of this study were to present a taxonomic synopsis for the genus Bifrenaria, detennining which taxa should be recognized, their distributions and which characters traditionally used to discriminate species are taxonomically informative. Identification keys, descriptions, distribution maps, and illustrations of the species are also provided

ASSUNTO(S)

filogenia botanica - classificação

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