Robert W. Freckmann Herbarium


Because of technology changes and personnel changes at UWSP and the Wisconsin State Herbarium, the database of plant species housed at this site was merged with the database from the OLD WisFlora website to create a new Flora of Wisconsin website at Currently we are encouraging all Wisplant viewers to begin using the Flora of Wisconsin website as soon as possible. Wisplants will remain operational through July 13th. After that date, all traffic to Wisplants will be redirected to the Flora of Wisconsin website.

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  Persicaria hydropiper (L.) Spach image
Photographer: Emmet J. Judziewicz           

Botanical Illustration

Botanical Illustration

Marion Sheehan
Family Polygonaceae
Persicaria hydropiper (L.) Spach
marsh-pepper knotweed, water-pepper
Persicaria: peach-like, the medieval name for knotweed
hydropiper: hydro for "water;" piper for "pepper"
County distribution map- click for detailed distribution maps.
Detailed Distribution:
Town Range Maps
Google Dot Maps
Status: Introduced - naturalized
Plant: erect to spreading, annual, 6"-24" tall, mostly smooth, often reddish, peppery tasting forb; stems nodes with short hairs, upper ones swelling with closed flowers; taprooted
Flower: greenish-pink, 4-or 5-parted, petals and petal-like sepals connected at the base; inflorescence thin, usually unbroken clusters arching or nodding near the tip; blooms July-Sept.
Fruit:brown/black, dull, dry seed
Leaf:alternate, narrowly lance-like, mostly less than 1" wide
Habitat: wet; marshes, streambanks

More Information Natural Communities Herbarium Specimens
All Persicaria list Ethnobotany Information Google- Images or Text

Flora of North America (off site)
Polygonum hydropiper L.
Polygonum hydropiper L. var. projectum Stanford

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