Page authors: Don Knoke, David Giblin
Equisetum telmateia
giant horsetail

Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to California, east to northern Idaho; Europe, northern Africa, and the Middle East.

Habitat: Moist areas in the lowlands.

Origin: Native

Growth Duration: Perennial

Conservation Status: Not of concern


Rhizomatous perennial, the stems dimorphic; sterile stems 5-30 dm. tall and 0.5-2 cm. thick, 20- to 40-ridged, the central cavity about 1/4 the diameter of the stem; stomates in 2 broad bands in the furrows; sheath 1-2.5 cm. long, with slender, tapered teeth 3-8 mm. long; fertile stems 2.5-6 dm. tall and 1.5-2 cm. thick; sheaths 2-5 cm. long, with 20-30 prominent teeth fused in groups of 2-4.


Branches only on sterile stems, whorled, ascending, 4- to 6-angled, solid, 1-2 mm. thick, sometimes again branched.


Cone 4-7 cm. long.

Accepted Name:
Equisetum telmateia Ehrh.
Publication: Hannover. Mag. 21: 287. 1783.

Synonyms & Misapplications:
(none provided)
Additional Resources:

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

WA Flora Checklist: Equisetum telmateia checklist entry

OregonFlora: Equisetum telmateia information

E-Flora BC: Equisetum telmateia atlas page

CalPhotos: Equisetum telmateia photos

45 photographs:
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