Virginia knotweed

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Virginia knotweed leaf

Virginia knotweed

Virginia knotweed

Virginia knotweed habit

Virginia knotweed flowers

Virginia knotweed

Virginia knotweed

Virginia knotweed

Virginia knotweed leaf

Virginia knotweed inflorescence

Morphology

Stem

Erect, simple or branched above, nearly glabrous or stiff-hairy.

Leaves

Alternate, short-stalked below, nearly sessile above, ovate to ovate-lanceolate, 1 to 6 inches long, to 3.5 inches wide, sparsely stiff-hairy; margins entire; tips tapering-pointed; stipules sheathing, tube-like; top margins fringed with short bristles.

Inflorescence

Racemes, slender, spike-like, to 12 inches long, sparsely flowered, somewhat arching, terminal and in upper leaf axils.

Flower

1-3 per cluster, spaced some distance apart, about 1/10 inch long; petals absent; perianth segments 4, petal-like, whitish to greenish, joined below; stamens 4; styles 2, extending beyond perianth edges.

Fruit

Achenes, egg-shaped, shiny, brown.

Ecology

Habitat

Woods, thickets and stream banks.

Distribution

East 1/2 of Kansas.

Practical Information

Uses

Native Americans treated whooping cough with a tea made from a mixture of Virginia knotweed leaves and the bark of the honey locust tree.

Additional Notes