[1] Diplacus douglasii occurs between 45 – 1200 meters elevation in the mountains and foothills of the Cascade and Sierra Nevada Ranges in California and Oregon.

[1] As a hydrophyte, it is generally found along the upper banks of small creeks,[1] and is classified as a facultative wetland species.

californicum) Columbine (Aquilegia formosa) Monkeyflowers "have become model systems for the study of evolutionary processes in nature[5]", because of their diversity in life history and morphology, varied reproduction (self-pollination to outcrossing) and ease to work with in experimental settings.

[15] Because of its affinity for serpentine soils, studying D. douglasii presents an opportunity to better understand adaptive traits in extreme environmental conditions.

Researchers have found that distinct populations of D. douglasii appear to have different environmental response thresholds for when they begin producing more cleistogamous versus open flowers.

[15] Understanding this mechanism could give scientists insight into how plants adapt to climatic shifts of warmer and drier conditions.