Cohniella lacera (Lindl.) Cetzal comb. nova is proposed here and Cohniella stipitata (Lindl.) Christenson is treated as its taxonomic synonym due to priority. Oncidium stipitatum Lindl. was incorrectly cited by various authors as validly published either in 1843 or 1844, when the correct date was 1846. In the meantime, Oncidium lacerum Lindl., previously considered one of its taxonomic synonyms, was described in 1844 and therefore has nomenclatural priority. I discuss the status and geographical distribution of Cohniella lacera comparing it with the morphologically similar species Cohniella nuda (Bateman ex Lindl.) Christenson. In addition, I include for each species a discussion of diagnostic characters, range of morphological variation, specimen citation, an illustration, and a distribution map. A key to distinguish the two species is also provided.