Phylogeny of the Bifrenaria (Orchidaceae) complex based on morphology and sequence data from nuclear rDNA internal transcribed spacers (ITS) and chloroplast trnL-trnF region

We investigated the monophyly and phylogenetic relationships of the genera Adipe (= Stenocoryne), Bifrenaria, Cydoniorchis, and Rudolfiella, on the basis of morphology and DNA sequence data. Sixteen species from the Bifrenaria complex and six related genera were sampled. Matrices were analyzed using maximum parsimony. Separate analyses of data partitions resulted in slightly different nonconflicting topologies; therefore, we combined all the data sets. The results support the monophyly of Bifrenaria and of Rudolfiella. Within Bifrenaria, two clades are strongly supported: the Amazonian clade and the southern Brazilian clade. Adipe is a paraphyletic group. Although Cydoniorchis is monophyletic and has many morphological synapomorphies, the acceptance of this genus would demand many nomenclatural changes. We propose recognizing a broad Bifrenaria. The results also indicate an Amazonian origin for Bifrenaria.