Bromus rigidus aka Ripgut Brome

Bromus rigidus is an annual grass known as ripgut brome. Another common name is great brome grass. It belongs to the grass family, Poaceae. Its range spans southern and western Europe, North Africa, and parts of western Asia. Sources differ on its status in Britain. PFAF includes Britain within its native range. The RHS lists it as non-native to Britain and Ireland.

This grass grows to about 3.3 feet (1 metre) tall. It completes its life cycle in one year. Its flowers contain both male and female organs. Wind carries pollen, but the plant can also fertilize itself. Some flowers stay closed and set seed through self-fertilization. PFAF gives May to June as the main flowering period. Its food-use account gives a broader April to June season. The seeds bear long, barbed awns that can cause injury.

It grows in ordinary garden soil with good drainage. It needs full sun and does not grow in shade. Sandy, loamy, and clay soils can all support it. It also grows in soil with few nutrients. It accepts mildly acid, neutral, and mildly alkaline conditions. Soil may be dry or moist, and established plants tolerate drought. It withstands strong winds but not exposure to sea winds. PFAF lists USDA zones 5–9 and UK zone 6. In Britain, records include waste ground on sandy Channel Island shores.

Seeds can be sown in place during spring or autumn. Cover them with only a thin layer of soil. PFAF reports germination within about two weeks. Yet its weed risk limits its value for garden beds. It has spread across California and the dry American Southwest. In North America, it invades rangeland and disturbed ground. It competes with native plants and causes problems for livestock grazing. Its barbed awns can injure livestock, pets, and people.

The cleaned seeds have a recorded food use. Native Californian groups gathered them for mush and other grain foods. Dried seed can be ground and mixed with water for gruel. The small grains make preparation slow and awkward. The awns must be removed before food preparation. These injury hazards differ from evidence of chemical poisoning. PFAF gives the plant a low food-use rating. It records no known medicinal uses or other uses.