Lady's Thumb

(Polygonum persicaria)

Lady's Thumb (Polygonum persicaria L.)

Identification: Flowers pink (sometimes white), small, arranged in tightly packed spikes. Stem swollen at the junction of a leaf and the stem, and with a papery sheath around the stem. Upper margin of the sheath with a fringe of hairlike spines. Stem and swollen nodes usually reddish. Stem without small, glandular hairs. Leaves elongate, narrow, tapering toward both the base and the apex, usually with two darker blotches along the midline of the leaf. Plant either erect or sprawling on the ground. Plant 6 to 24 inches in height.

Distribution: Throughout most of North America.

Habitat: Lady's Thumb is found in disturbed habitats such as lawns, fields, empty lots, and along roadsides.

Flowering period: June to October.

Similar Species: Lady's Thumb is easily mistaken for Pennsylvania Smartweed. The leaves of Pennsylvania Smartweed lack darker blotches along the midline of the leaf and the stem sheathes lack hairlike spines along their dorsal edge.