G.S.Varad. & Forero (L.B.Sm. & Read) 1987 - Varadarajan GS, Forero E (1987) Genus Pitcairnia (Bromeliaceae): New Taxa from Colombia, Nomenclatural Changes, and Species Complexes. Systematic Botany 12: 410-415. doi: 10.2307/2419266.
There is no corrections for Pitcairnia occidentalis var. alversonii yet.