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Bromus diandrus - ripgut brome

Scientific Family
Poaceae
Synonyms
Anisantha diandra, A. gussonii, Bromus diandrus var. gussonei,  B. gussonii, B. rigidus subsp. gussonei and more. See SEINET.
Other common names
ripgut grass
Plant type
Grasses
Riparian
No

Grass Description

Origin
Introduced
Season
Cool

Grows in disturbed ground, waste places, fields, sand dunes, and roadsides.

Plant Community
Disturbed Areas
Low elevation
1000
High elevation
6600

General Description

Erect or bending annual, 8 to 35 inches tall, height depends on moisture. Seedhead with long awns.

Weedy annual plants; sheaths hairy; no auricles; ligules 1/16 inch; seedhead open with spreading branches; spikelets cylindrical; awns 1-1/2 to 2 inches long, not twisted; narrow lemmas with two teeth up to ¼ inch long point.

Grass type
Annual
Rhizomes
No
Stolons
No
Clump Diameter 2 ft or more
No
Bushy - highly branched
No
Height with Seedheads
24 inches or more
Seedhead Structure
Branched - open and spreading
Seedhead droops
Yes
First bloom month
April
Last bloom month
July

Flower Characteristics

Flowers per Spikelet
Multi-flowered
Spikelets One-Sided
No
Awns
Greater than 1 inch
Three Awns
No
Awns bent
No
Flower and Seedhead Notes

Seedhead is open, drooping, 3 to 6 inches long, lower branches are shorter, 3/8 to 3/4 inches long. Spikelets of 5 to 7 florets. Lemmas may be hairy. Awns long and strong.

Vegetative Characteristics

Blade is hairy
Yes
Blade margins white
No
Blade cross-section
Flat
Involute – rolled inward on upper surface

Blades hairy and flat on both sides, 4 to 8 inches long, 1/8 to 1/2 inch wide. Edges of blade roll inward when dry.

Sheath is hairy
Yes
Tufts of hair top of sheath or collar
No
Ligule
Membranous
Auricles
No

Excellent in seedling stage and during vigorous vegetative growth, but poor to fair upon flowering and poor when mature. The name ripgut brome suggests possible damage to animals if they consume the sharp, long-awned florets of this species.