[floranorthamerica.org] Bract Color Variations: Most populations have either red or yellow bracts, with only occasional individual plants of the other color. Yellow populations are found primarily in Marin and southern Sonoma counties southward and are gradually replaced by red populations from northern Sonoma County northward. Mixed color populations occur in a few places, especially in San Mateo County. (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: 03/31/2025).
