Oriental lady's thumb USDA PLANTS SYMBOL: PELO10
Persicaria longiseta (Bruijn) Kitagawa
Synonym(s): Asiatic smartweed, bristled knotweed, bunchy knotweed

Oriental lady’s thumb is an annual forb that can reach 6-30 in. (15.2-76.2 cm) in height and can be either erect or sprawling. Leaves are elongate, narrow and pointed at the base and tip. Stems have swollen nodes with papery sheaths (ocrea). Ocrea have long, hair-like bristles on the margin. Flowering occurs from June to October, when pink flowers develop at the apex of the stems. Flowers are 1/8 in. (0.3 cm) long and occur in groups. Oriental lady’s thumb is native to Asia and occurs in disturbed habitats such as along roadsides and in pastures. Plants also inhabit wet areas.

Identification, Biology, Control and Management Resources