Page authors: Don Knoke, David Giblin
Apera interrupta
dense silky-bent

Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains; also in the central U.S., Great Lakes region, and northeastern U.S.

Habitat: Dry wasteland and other disturbed areas in shrub-steppe and open coniferous forests.

Flowers: May-July

Origin: Introduced from Europe

Growth Duration: Annual

Conservation Status: Not of concern

Pollination: Wind


Tufted to single-stemmed, glabrous annual, the culms 1-4 dm. tall.


Sheaths open; ligules 2-3 mm. long, truncate and lacerate; blades flat to folded, 1-3 mm. broad.


Inflorescence a narrow, greenish, interrupted panicle 5-10 cm. long; spikelets 1-flowered, articulate above the glume; first glume scarcely 2 mm. long, the second nearly 3 mm.; lemma 2 mm. long, with an awn 6-7 mm. long attached near the tip; palea subequal to the lemma; rachilla prolonged as a bristle about 0.5 mm. long; lodicules 2, 0.5 mm. long.



Accepted Name:
Apera interrupta (L.) P. Beauv.
Publication: Ess. Agrostogr. 31, 151. 1812. 1812.

Synonyms & Misapplications:
Agrostis interrupta L. [HC]
Additional Resources:

PNW Herbaria: Specimen records of Apera interrupta in the Consortium of Pacific Northwest Herbaria database

WA Flora Checklist: Apera interrupta checklist entry

OregonFlora: Apera interrupta information

E-Flora BC: Apera interrupta atlas page

CalPhotos: Apera interrupta photos

18 photographs:
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