Hardiness ratings: USDA zone 5b - 7
- Wikipedia. Online encyclopedia entry (if defined).
- Google images. Web search for photographs.
- GRIN. Taxonomical details, with common names, distribution, and synonyms.
- The Plant List. Taxonomical lookup
Links for Penstemon californicus
- American Penstemon Society - Detailed description of the species' botanical characteristics, habitat, and native range. (1 photo)
- Dave's Garden PlantFiles - Profile page with horticultural basics, and member-contributed photos and comments. (zone 5b-7) (2 photos)
- NARGS Image Gallery - Photograph(s) contributed by North American Rock Garden Society members. (1 photo)