Page authors: David Giblin, Ben Legler
Lycopus americanus
cut-leaf water-horehound

Distribution: Both sides of the Cascades in Washington; throughout most of North America.

Habitat: Nonalkaline wetland, riparian, pond and lakeshore sites at low to moderate elevations.

Flowers: June-August

Origin: Native

Growth Duration: Perennial

Conservation Status: Not of concern


Perennial herbs from elongate rhizomes, the simple or branched square stems 2-8 dm. tall, glabrous except for the hairy nodes.


Leaves opposite, all cauline, numerous, lanceolate, 3-8 cm. long and 1-3.5 cm. wide, tapering to a short petiole, irregularly deeply toothed, the lower teeth the larger.


Flowers sessile, verticillate in the axils of scarcely reduced leaves; calyx with 5 firm, narrow, sharp-pointed lobes; corolla white, small, about equally 4-lobed, 2-3 mm. long, about equaling the calyx; fertile stamens 2, barely exerted, sterile stamens 2, small, club-shaped; style 2-parted; ovary 2-celled, superior.


Nutlets 4, with corky ridges around the tip.

Accepted Name:
Lycopus americanus Muhl. ex W.P.C. Bartr.
Publication: Fl. Philadelph. Prodr. 15. 1815.

Synonyms & Misapplications:
(none provided)
Additional Resources:

PNW Herbaria: Specimen records of Lycopus americanus in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Lycopus americanus checklist entry.

E-Flora BC: Lycopus americanus atlas page.

CalPhotos: Lycopus americanus photos.

USDA Plants: Lycopus americanus information.

11 photographs:
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