[Wikipedia] Sole Species, Range, Habitat: It is the sole species in genus Simpsonanthus. It is native to the southwestern United States and northern Mexico, where it grows in desert mountains and flats in scrub and woodland habitat. (link added by Mary Ann Machi)
Calflora:
Information on California plants for education, research and conservation,
with data contributed by
public and private institutions and individuals.
[web application]. 2025.The Calflora Database
[a non-profit organization].Available:
https://www.calflora.org/(Accessed: 05/08/2025).
