[Wikipedia] Flower Description: The flowers are 5 - 8 cm diameter, with 5 papery white petals, usually with a red to maroon spot at the base, surrounding the yellow stamens and pistils. (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. Berkeley, California:The Calflora Database
[a non-profit organization].Available:
https://www.calflora.org/(Accessed: 02/10/2025).