Page authors: Don Knoke, David Giblin
Achnatherum hendersonii
Henderson's needlegrass

Distribution: Occurring east of the Cascades crest in Douglas, Kittitas, and Yakima counties; central Washington to Jefferson County, Oregon.

Habitat: Dry, rocky, shallow soil, in sagebrush desert or ponderosa pine forest openings.

Flowers: May-June

Origin: Native

Growth Duration: Perennial

Conservation Status: Not of concern

Pollination: Wind


Densely tufted perennial, the culms semi-solid, terete, 1-3 dm. tall, smooth.


Sheaths open, finely puberulent; ligules puberulent externally, the lower ones up to 0.5 mm. long, the upper ones to 1 mm. long; blades strongly involute, erect, 1 mm. broad, somewhat puberulent.


Inflorescence a narrow panicle 4-12 cm. long, often partially included in the sheath, the branches stiff, nearly erect; spikelets 1-flowered, articulate above the glumes; glumes 5-nerved, obtuse, the first 4.5 mm. long, the second slightly longer; lemma about equal the glumes, glabrous, olive or brown, with a terminal, pubescent awn 6-10 mm. long; palea nearly as long as the lemma; stamens 3, the anthers purple; lodicules 3, oblong-elliptic, about 1.5 mm. long.



Accepted Name:
Achnatherum hendersonii (Vasey) Barkworth
Publication: Phytologia 74(1): 7. 1993.

Synonyms & Misapplications:
Eriocoma hendersonii (Vasey) Romasch.
Oryzopsis hendersonii Vasey [HC]
Stipa hendersonii (Vasey) Mehlenb.
Additional Resources:

PNW Herbaria: Specimen records of Achnatherum hendersonii in the Consortium of Pacific Northwest Herbaria database

WA Flora Checklist: Achnatherum hendersonii checklist entry

OregonFlora: Achnatherum hendersonii information

E-Flora BC: Achnatherum hendersonii atlas page

CalPhotos: Achnatherum hendersonii photos

4 photographs:
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