Page authors: Don Knoke, David Giblin
Poa annua
annual bluegrass
Specimens
Photos

Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.

Habitat: Lawns, fields, parking lots, sidewalks, roadsides, wastelots, prairies and grassy balds, and other disturbed, open areas.

Flowers: March-August

Origin: Introduced from Eurasia

Growth Duration: Annual, Biennial

Conservation Status: Not of concern

Pollination: Wind

Description:
General:

Glabrous annual, the culms 5-20 cm. tall, hollow, rooting at the nodes and forming mats.

Leaves:

Sheaths closed below, but open over half their length; ligules about 1 mm. long, rounded to truncate; blades 1-3.5 mm. broad, usually folded, the tip prow-like.

Flowers:

Inflorescence a pyramidal panicle 3-8 cm. long, the branches spreading and somewhat rigid; spikelets 3- to 6-flowered, 4-6 mm. long; glumes unequal, the first 1-nerved, about 2 mm. long, the second 3-nerved, much the broader; florets rather distant, the rachilla visible; lemmas about 3.5 mm. long, 5-nerved, the margins purplish and papery, usually pubescent along the keel and marginal nerves; paleas slightly shorter than the lemmas, 2-keeled.

Accepted Name:
Poa annua L.
Publication: Sp. Pl. 1: 68. 1753.

Synonyms & Misapplications:
Poa annua L. var. aquatica Asch.
Poa annua L. var. reptans Hausskn.
Additional Resources:

PNW Herbaria: Specimen records of Poa annua in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Poa annua checklist entry.

OregonFlora: Poa annua information.

E-Flora BC: Poa annua atlas page.

CalPhotos: Poa annua photos.

USDA Plants: Poa annua information.

19 photographs:
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