From Plant Press, Vol. 21, No. 2, April 2018.
Reported from southeastern Arizona and southwestern New Mexico, Hymenoxys ambigens is comprised of three local varieties. Variety neomexicana is known from the rocky slopes of the Animas and Peloncillo Mountains of New Mexico, and is ranked as imperiled (T2, NatureServe status). In the cover story in this issue of The Plant Press, Robert Edwards finds that soil pH is a strong environmental variable that is uniquely correlated with diversity in the tribe Heliantheae. Tangerini illustrated this variety for Warren Wagner in his treatment of the species in Brittonia (51: 79-86; 1999).