The invasive knotweeds in Wisconsin are herbaceous perennials with a shrub-like appearance. They have multiple, hollow, arching stems in clumps that resemble bamboo. Stems have swollen nodes. Leaves are alternate and oval-shaped with pointed tips. Clusters of tiny white flowers arise along the stems in late summer and mature into flat seeds.

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Look Alikes

The perennial knotweeds look very similar to each other but are distinct from other species.

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