Erect Knotweed

(Polygonum erectum)

Erect Knotweed (Polygonum erectum L.)

Identification: A upright plant. Flower with green sepals with yellow or white margins. Flowers either solitary or in pairs in the leaf axils. Stem not highly branched, with swollen nodes at the junction with a leaf, and with a papery sheath. Papery sheath rapidy becoming shredded and torn. Leaves ovate, tapering toward either end and with short petioles. Plant 4 to 36 inches in height.

Distribution: Throughout most of North America.

Habitat: Erect Knotweed is found in dry disturbed areas, particularly empty lots and fields.

Flowering period: August to October.

Similar Species: Bushy Knotweed is highly branched with small, almost needlelike, leaves. Prostrate Knotweed straggles along the ground and is not erect. The leaves of Prostrate Knotweed are small and narrower than those of Erect Knotweed.