Tufted Knotweed (Smartweed)

Scientific Name - Polygonum caespitosum Blume
var. longisetum (DeBruyn) A.N. Stewart
Family - Polygonaceae

Erect to sprawling summer annual with smooth round stems and swollen nodes. Leaves, alternate, smooth above, sparsly-hairy on veins below, elliptic-to lance shaped, joined to stem with a sheathing membrane tipped with long hairs. Deep pink to nearly red flowers in spikes at tips of stems. Reproduces by seed. Found from Massachusetts to Illinois, south to north Florida and Louisiana. Native to Asia.