[Wikipedia] Range, Prehistoric Range: It is a species of prickly pear native to the southwestern United States and northern Mexico. Some analysis of the prehistoric range of O. chlorotica has been conducted by studies in the Waterman Mountains of Arizona; these pollen core analyses indicate that this cactus species was present in northern Arizona in late Wisconsinan glaciation period. (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: 03/30/2025).
