[Wikipedia] Range, Habitat: Oxytheca perfoliata is a species of flowering plant in the buckwheat family known by the common names round-leaf puncturebract and roundleaf oxytheca. It is native to the southwestern United States, where it is a common plant of the deserts and some woodland and valley areas. (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).