Flowers: sepals 2–3(–5) mm; petals 3–5(–7) mm; stigma hemispheric, usually exserted beyond anthers of longer stamens at anthesis. 2n = 28.

Flowering May–Sep. Open pine forests, sagebrush slopes, dry margins of meadows; 500–2500 m; Calif., Idaho, Mont., Nev., Oreg., Wash., Wyo.

Subspecies diffusum is very similar to Gayophytum eriospermum but is not known from the area of distribution of the latter.