Page authors: Don Knoke, David Giblin
Eleocharis acicularis
needle spikerush

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

Habitat: Marshes, muddy shores, and other wet places.

Flowers: June-September

Origin: Native

Growth Duration: Annual, Perennial

Conservation Status: Not of concern

Pollination: Wind


Very slender perennial from slender, branching rhizomes, forming dense tufts; culms filiform, 3-12 cm. tall, the basal sheaths pale or purplish.


Leaves all basal and reduced to sheaths.


Spikelet solitary and terminal, 2.5-7 mm. long, 3- to 15-flowered; scales of the spikelets spirally arranged, 1.5-2.2 mm. long, translucent, with a greenish midrib and paler margins; perianth of 3-4 bristles, equaling the achene, or wanting; stamens 3; style trifid, thickened at the base.


Achenes white to pale gray, 0.7-1.1 mm. long, with a conic tubercle (the thickened base of the style), the body obovoid, longitudinally 8- to 18-ribbed.

Accepted Name:
Eleocharis acicularis (L.) Roem. & Schult.
Publication: Syst. Veg. 2: 154. 1817. 1817.

Synonyms & Misapplications:
Eleocharis acicularis (L.) Roem. & Schult. var. gracilescens Svenson
Eleocharis acicularis (L.) Roem. & Schult. var. occidentalis Svenson
Eleocharis acicularis (L.) Roem. & Schult. var. porcata S.G. Sm.
Eleocharis acicularis (L.) Roem. & Schult. var. submersa (Nilsson) Svenson
Scirpus acicularis L.
Additional Resources:

PNW Herbaria: Specimen records of Eleocharis acicularis in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Eleocharis acicularis checklist entry.

OregonFlora: Eleocharis acicularis information.

E-Flora BC: Eleocharis acicularis atlas page.

CalPhotos: Eleocharis acicularis photos.

USDA Plants: Eleocharis acicularis information.

31 photographs:
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