Greenwoodiella

KEY TO THE SPECIES AND VARIETIES Of GREENWOODIELLA View in CoL

1. Plants from the Chihuahuan Desert region (southern Texas in the U. S. A., Tamaulipas, and probably intervening areas in Coahuila and Nuevo León in northeastern Mexico) ; labellum with a transverse, fleshy ridge about one third of its length from the base; hypochile of labellum with a large yellow blotch; epichile of labellum provided with 5 green veins, deeply emarginate.................................................. G. deserticola View in CoL

1. Plants from Central Mexico southward to Costa Rica, Cuba, and the Dominican Republic; labellum lacking a transverse ridge; hypochile of labellum white, sometimes with faint purplish-brown veins; epichile of labellum with a single central, purplish-brown or pinkish-brown vein (sometimes a few additional, fainter veins are present on the hypochile), truncate, obtuse, rounded, obscurely apiculate or shallowly emarginate...................... 2

2. Hypochile ellipsoid to rhombic, distinctly expanded into rounded lobes at each side, greatest expansion at about the middle of the whole labellum; epichile truncate or obscurely apiculate when fully spread out......................................................... G. wercklei View in CoL

2. Hypochile oblong to narrowly obovate, the expanded portion above the middle; epichile rounded, obtuse or shallowly emarginate when fully spread out............................................. 3 ( G. micrantha View in CoL )

3. Flowers auto-pollinating; column often lacking a rostellum; pollinia fused at base to the stigma at anthesis, impossible to remove without breaking.............................................................. G. micrantha var. micrantha View in CoL

3. Flowers cross-pollinating; column with a well-developed rostellum; pollinia free from the stigma at anthesis, can be removed whole............................................................................. G. micrantha var. garayana View in CoL