[Wikipedia] Range, Species Separation: It is found mainly in Oregon and California, but it is endemic to the United States. The plant was formerly considered to be part of T. menziesii but was split off as a separate species because while T. menziesii is tetraploid, T. diplomenziesii is diploid.[ (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: 04/07/2025).
