P.J.Cribb & Podz. (Summerh.) 1979 - Podzorski AC, Cribb PJ (1979) A Revision of Polystachya sect. Cultriformes (Orchidaceae). Kew Bulletin 34(1): 147-186. doi: 10.2307/4117980.
There is no corrections for Polystachya caespitifica subsp. latilabris yet.