A New Species in Lophiaris (Orchidaceae, Oncidiinae), in the Lophiaris straminea Complex

An undescribed species of Lophiaris Rafinesque (Orchidaceae, Cymbidieae, Oncidiinae) was detected while conducting a phylogenetic study of Trichocentrum Poeppig & Endlicher s.l. Lophiaris sierracaracolensis Cetzal & Balam is described from Sierra Caracol in the Central Depression of Chiapas, on the Pacific slopes of Mexico. The new species is illustrated, and its affinities are discussed. The novelty is related to L. straminea (Bateman ex Lindley) Braem, but the labellum isthmus is broader (to 3 mm wide), the claw of the dorsal sepal is very short (1.5 mm long) and wide, and the callus is 8-partite (vs. 5-partite in L. straminea).