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Lycopus americanus (American water horehound)
Smith, R.W.

Lycopus americanus

Lycopus americanus Muhl. ex W.P.C. Barton

American Water Horehound, Water Horehound

Lamiaceae (Mint Family)

Synonym(s): Lycopus americanus var. longii, Lycopus americanus var. scabrifolius, Lycopus sinuatus


USDA Native Status: L48 (N), CAN (N)

Tiny, white, tubular flowers clustered in dense groups around a square stem in axils of opposite leaves.

The members of this group are non-aromatic mints and are typical of wet sites. The various species are distinguished on the basis of technical details. They are sometimes called bugleweeds because of the resemblance of each flower to a bugle. Other species have less coarsely toothed leaves. The genus name is from the Greek lycos ("a wolf") and pous ("foot") and refers to the likeness of some species' leaves to a wolf's footprint. About 10 species of Lycopus occur in eastern North America; most are very similar, making identification difficult.


From the Image Gallery

2 photo(s) available in the Image Gallery

Plant Characteristics

Duration: Perennial
Habit: Herb
Size Notes: Up to about 20 inches tall.
Leaf: Green
Fruit: Nutlets, 4.

Bloom Information

Bloom Color: White , Purple
Bloom Time: Jun , Jul , Aug , Sep
Bloom Notes: White, often with purple spots.


USA: AL , AR , AZ , CA , CO , CT , DC , DE , FL , GA , IA , ID , IL , IN , KS , KY , LA , MA , MD , ME , MI , MN , MO , MS , MT , NC , ND , NE , NH , NJ , NM , NY , OH , OK , OR , PA , RI , SC , SD , TN , TX , UT , VA , VT , WA , WI , WV , WY
Canada: NB , NL , NS , PE
Native Distribution: Throughout North America, except far north and Nevada.
Native Habitat: Moist sites, shorelines, and wetlands.

Growing Conditions

Water Use: High
Light Requirement: Shade
Soil Moisture: Moist , Wet
CaCO3 Tolerance: Medium


Conspicuous Flowers: yes

Find Seed or Plants

Find seed sources for this species at the Native Seed Network.

National Wetland Indicator Status

This information is derived from the U.S. Army Corps of Engineers National Wetland Plant List, Version 3.1 (Lichvar, R.W. 2013. The National Wetland Plant List: 2013 wetland ratings. Phytoneuron 2013-49: 1-241). Click here for map of regions.

From the National Organizations Directory

According to the species list provided by Affiliate Organizations, this plant is on display at the following locations:

Native Seed Network - Corvallis, OR

Web Reference

Webref 23 - Southwest Environmental Information Network (2009) SEINet - Arizona Chapter

Additional resources

USDA: Find Lycopus americanus in USDA Plants
FNA: Find Lycopus americanus in the Flora of North America (if available)
Google: Search Google for Lycopus americanus


Record Modified: 2023-04-06
Research By: TWC Staff

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