Synonyms:
Status: Basionym
Publ: Phytologia 6: 257 (1958)
Type: Type in the U. S. National Herbarium, No. 2,216,850, collected on perpendicular rocks near Tequisistlan, State of Oaxaca, Mexico, altitude 900-1200 meters, April 1, 1957, by M. B. Foster and O. C. Van Hyning (No. 2937).
Description: click here.
Taxonomic Change: