<i>Encyclia</i>, <i>Epidendrum</i>, or <i>Prosthechea</i>? Clarifying the Phylogenetic Position of a Rare Amazonian Orchid (Laeliinae-Epidendroideae-Orchidaceae)

Abstract— The phylogenetic position of a rare orchid species, which was described by Mansfeld from the Brazilian Amazon, is discussed. Although originally described under Epidendrum despite having a column that is not fully adnate to the lip claw, a feature not common in this genus, Epidendrum apuahuense has been transferred to Encyclia and Prosthechea by other authors. About 90 yr after its description, we found a new population of this species in Brazil, which allowed us to study its taxonomy. A phylogenetic reconstruction was performed using nuclear (ITS rDNA) and plastid ( matK exon, rpl32-trnL spacer, trnL intron, and trnL-trnF spacer) datasets, aiming to clarify the generic placement of this taxon. Our results strongly support keeping E. apuahuense under Epidendrum . We also neotypify this name, since the original specimens were destroyed and no illustration is available. The morphological affinities of E. apuahuense and allied taxa are discussed.