Bletia mixtecana, a new species from Oaxaca, Mexico is described and illustrated. This species is florally similar to B. parkinsonii but differs in its aerial thickened stems ('pseudobulbs') and several floral attributes. A phylogenetic analysis of nuclear ribosomal ITS DNA sequences indicates that B. mixtecana and B. parkinsonii are not closely related, suggesting that floral similarity represents either parallelism or shared ancestral (symplesiomorphic) traits. The new species is a strict gypsophile known only from two populations and it qualifies as endangered based on the small number of known populations and individuals, high habitat specificity and the observed loss of plants at one of the two known locations.