[Wikipedia] Etymology, John Muir Favorite: The Latin specific epithet newberryi honors the American geologist and botanist John Strong Newberry (1822-1892).
Penstemon newberryi was the favorite flower of naturalist John Muir. (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).