Phylogenetic Position ofCentroglossaandDunstervillea(OrnithocephalusClade: Oncidiinae: Orchidaceae) Based on Molecular and Morphological Data

Abstract

Abstract—Even though the monophyly of theOrnithocephalusclade (Oncidiinae) is currently well defined, the systematic positioning ofCentroglossaandDunstervillearemains obscure in the clade due to the absence in previous phylogenetic studies.Centroglossahas a very similar habit and is indistinguishable fromZygostates, whereasDunstervilleahas as its main characteristic the calcarate labellum, also found inCentroglossa.We clarify the systematic and phylogenetic positioning ofCentroglossaandDunstervilleain theOrnithocephalusclade (OC) through analysis of maximum likelihood, Bayesian inference, and maximum parsimony from molecular data (nrITS andmatKcpDNA) and morphology. Our results indicate thatDunstervilleais phylogenetically close toEloyella; both genera have a psigmoid habit, single-sided and flattened leaves, floral perianth with the same coloring, petals with entire margins, and a short rostellum.Centroglossaappears as a subclade withinZygostates. In addition to several homoplastic features, these two genera have the dorsal position of viscidium as a synapomorphy. The calcarate labellum, common toCentroglossaandDunstervillea, originated more than once in the OC. Based on the phylogenetic results, we propose the nomenclatural changes to includeDunstervilleainEloyellaandCentroglossainZygostates. New synonyms are indicated toZygostates greenianaandZ. nunes-limaeand lectotypes are indicated toCentroglossa macrocerasandC. glaziovii.