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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  Polygonum aviculare L. subsp. depressum (Meisn.) Arcang. image
Photographer: Janice Stiefel           

Emmet J. Judziewicz

Robert R. Kowal

Janice Stiefel
Family Polygonaceae
Polygonum aviculare L. subsp. depressum (Meisn.) Arcang.
door-yard knotweed, oval-leaved knotweed
Polygonum: derived from the Greek words polys, "many," and gonu, "knee or joint," hence "many joints" because of the thickened joints on the stem
aviculare: relating to small birds
County distribution map- click for detailed distribution maps.
Detailed Distribution:
Town Range Maps
Google Dot Maps
Status: Introduced - naturalized
Plant: matting, annual forb; stems with many branches, nodes 2-parted and becoming jagged
Flower: white to pink-edged, 5-parted, petals and petal-like sepals joined at base, with flat or rounded tips, outer 3 not longer than the other 2; inflorescence small clusters from the leaf axils
Fruit:dark brown, dull, dry seed
Leaf:alternate, bluish-green, all alike, mostly 2-5 times as long as wide, bases jointed
Habitat: disturbed sites, sidewalks, streets

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

Flora of North America (off site)
Polygonum aequale Lindm.
Polygonum arenastrum Boreau
Polygonum aviculare L. var. arenastrum (Boreau) Rouy
Polygonum montereyense Brenckle

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