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Statewide IPM Program, University of California

Bromegrasses  (Bromus spp. )

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Life stages of Bromegrasses inflorescence collar mature plant ripgut brome collar ripgut brome flower head

Bromegrasses consist of a large group of species including both perennial and annual grasses. Some are valuable as forage and others are important weeds. The photos here show Bromus hordeaceous, soft brome, also called soft chess and ripgut brome, B. diandrus. Soft brome is a widely distributed annual at low elevation areas in California, especially in open, disturbed sites. Ripgut brome is a cool season annual grass. Although found throughout California, it is most abundant in the central and southern parts of the state. Other common bromegrasses found in California agricultural situations include rescuegrass, B. catharticus, and downy brome, B. tectorum.

Collar

Most species have membranous ligules but no auricles.

Mature plant

Soft brome plants are distinguished by dense soft hairs on the sheath.

Flowers

Most species have long spikelets with needlelike awns.

  • Ripgut brome has long spikelets with needlelike awns, 1 to 2 inches (2.5–5 cm) long.
  • Rescuegrass, is awnless or has awns no longer than 3/25 of an inch (3 mm).
  • Downy brome is quite hairy and has awns about one-half inch long.
  • Soft brome plants are distinguished by compact spikelets with awns about 1/4 to 1/2 inch long (6.4–13 mm) long.

Related or similar plants

  • Soft brome, Bromus hordeaceus
  • Ripgut brome, Bromus diandrus
  • Rescuegrass, Bromus catharticus
  • Downy brome, Bromus tectorum

More information