It usually germinates in the fall, lies over winter, and produces seed early in the spring. It has smooth, slender, erect stems. The plant grows 6 inches to 2 feet high from a much-branched base. The sheathes and leaves are covered with fine, soft hair. The head is much-branched and somewhat drooping.
Seeds are long and flat with an awn about as long as the seed.
It matures and sets seed early spring, before most other grass species or crops. Downy brome is a strong invader and creates a serious fire hazard when the mature plant dries. Mature plants turn purple or brown. It grows in fields, waste places, roadsides, and is widely distributed in Colorado from 4,000 to 9,000 feet. It is a serious small grain problem.