Page author: Don Knoke
Equisetum arvense
common horsetail, field horsetail
WTU specimens
Other herbaria

Distribution: Cosmopolitan; throughout the Pacific Northwest

Habitat: Moist to moderately dry areas

Origin: Native

Conservation Status: Not of concern

Description:
General:

: Rhizomatous annual, the stems dimorphic; sterile stems 1.5-6 dm. tall and 1.5-5 mm. thick, prominently 10- to 12-ridged, the central cavity about 1/4 the diameter of the stem; stomates in 2 broad bands in the furrows; sheath 5-10 mm. long, greenish, with teeth 1-3 mm. long, free, firm and brown; fertile stems brownish to whitish, soon withering, simple, up to 3 dm. tall and 8 mm. thick, with sheaths 14-20 mm. long, and large teeth 5-9 mm. long.

Leaves:

Branches only on sterile stems, whorled, ascending, 3- or 4-angled, solid, 1-1.5 mm. thick, sometimes again branched.

Spores:

Cone 0.5-3.5 cm. long, long-pedunculate, blunt.

Accepted Name:
Equisetum arvense L.
Publication: Sp. Pl. 2: 1061. 1753. 1753.

Synonyms:
Equisetum arvense L. var. boreale (Bong.) Rupr.
Additional Resources:

PNW Herbaria: Specimen records of Equisetum arvense in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Equisetum arvense checklist entry.

E-Flora BC: Equisetum arvense atlas page.

CalPhotos: Equisetum arvense photos.

USDA Plants: Equisetum arvense information.

31 photographs:
Group by