California brome is a cool-season perennial bunchgrass.
Roots are deep and wide-spreading.
In the greenhouse, both open-pollinating and cleistogamous florets were produced on the same plant when soil was dry during flower development. Plants produced only open-pollinating florets when soil was moist during flower development. Germinative capacity of fresh California brome seed is 85 to 90 percent under laboratory conditions. It is unclear whether long-term seedbanking is an important regeneration strategy for California brome. Viability may be longer, however.