FLOWERS: Crown hoods broadly rounded dorsally from base to apex, attenuate above the middle and abruptly contracted at the tip to a pair of erect or recurved tooth-like lobes.

NOTES: See also parent taxon. High desert and chaparral ofn AZ: Coconino, Mohave cos.; 1450-1600 m (4800-5300 ft); May-Jun; e CA, NV, UT, s WY, s to n AZ, w CO.

REFERENCES: Sundell, Eric. 1994. Asclepiadaceae. J. Ariz. - Nev. Acad. Sci. Volume 27, 169-187.