Prostrate knotweed

Polygonum aviculare L.

Life cycle

Prostrate, mat-forming summer annual.

prostrate knotweed plant
Prostrate knotweed plant.


Alternate, narrow oval to oblong leaves with pointed tips, smooth margins and short petioles.

prostrate knotweed seedling
Prostrate knotweed seedling


Prostrate, tough, wiry stems with distinct nodes are highly branched and mat-forming. Plants perform well in compacted areas. A membranous sheath (ocrea) surrounds the stem at the base of each petiole.

prostrate knotweed ocrea
Prostrate knotweed ocrea.

Flowers and fruit

Small, inconspicuous flowers are white to pinkish and clustered in the leaf axils. The seed is enclosed in a single-seeded, dark reddish brown, three-sided fruit.

prostrate knotweed flower
Prostrate knotweed leaf and flower.



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The MSU IPM Program maintains this site as an access point to pest management information at MSU. The IPM Program is administered within the Department of Entomology, fueled by research from the AgBioResearch, delivered to citizens through MSU Extension, and proud to be a part of Project GREEEN.