The stems are straight and very spiney. Leaves are medium to dark matte green and typically have seven leaflets. R. californica seems immune to mildew and rust. It does get a little blackspot when stressed, but doesn't seem to lose any leaves to it. The fragrant flowers open from long pointed buds.
Flower color varies from cool medium pink to white.
Flowers are produced in clusters of various sizes. May. Here it begins in early June, and blooms continuously for over four months. In October, thickets often display flowers and ripe hips simultaneously. R. californica is a member of the Cassiorhodon section of the subgenus Eurosa of the genus Rosa . There are many species in the Cassiorhodon section, including R. rugosa , R. arkansana , and R. nutkana .