Page author: Don Knoke
Bromus diandrus
great brome, ripgut brome, ripgut grass
WTU specimens
Other herbaria

Distribution: Introduced from British Columbia to Baja California, mostly west of the Cascades in Washington, but east to Idaho and Colorado.

Habitat: A weed of waste ground and along highways and railroads.

Flowers: April - June

Origin: Introduced

Conservation Status: Not of concern


Annual, the culms 4-8 dm. tall, usually glabrous.


Leaf blades flat, 3-10 mm. wide; sheaths with soft, spreading hairs; ligules lacerate, 3-5 mm. long; auricles lacking.


Inflorescence a spreading to erect panicle 10-15 cm. long, the branches elongate, bearing only 1-2 spikelets; spikelets 5- to 7-flowered, 2.5-4 cm. long, broadest above mid-length; glumes glabrous, narrowly lanceolate, the first 1-nerved, 15-20 mm. long, the second 3-nerved, 25-33 mm. long; lemmas 25-30 mm. long, puberulent, the 2 teeth slender, 3-4 mm. long, the awn attached between the teeth 3.5-6 cm. long, straight; stamens 3.

Accepted Name:
Bromus diandrus Roth
Publication: Botanische Abhandlungen und Beobachtungen. 1787.

Synonyms & Misapplications:
Anisantha rigida (Roth) Hyl.
Bromus diandrus Roth ssp. rigidus (Roth) LaĆ­nz
Bromus maximus Desf.
Bromus rigidus Roth [HC]
Additional Resources:

PNW Herbaria: Specimen records of Bromus diandrus in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Bromus diandrus checklist entry.

E-Flora BC: Bromus diandrus atlas page.

CalPhotos: Bromus diandrus photos.

USDA Plants: Bromus diandrus information.

25 photographs:
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