The American species of Limnorchis and Piperia, north of Mexico - Rydberg, Per Axel 1860-1931 (New York : [editor no identificado], 1901)
"[Reprinted from the Bulletin of the Torrey botanical club 28, 25 Nov., 1901]"
Keywords: ORQUIDEAS -- MEXICO; ORQUIDEAS -- IDENTIFICACION -- MEXICO