Lady's Thumb

Lady's Thumb
Lady's Thumb. Polygonum persicaria, also Persicaria maculosa.
Polygonaceae, the buckwheat, smartweed or knotweed family.

Plant: Ascending to prostrate, often branching plant 6"-24", with dense cylindrical clusters of small pink flowers, and narrow leaves with a dark blotch in the center. Stems often pinkish. Perennial
Flowers: Tiny, pink, about 1/6" across, in dense, cylindrical spikes 1/2"-2" long. Four to six (often five) petal-like sepals; petals are absent.
Leaves: Alternate, lanceolate, 2"-6", usually with a dark blotch in the center. Petioles very short, margins smooth. Stem has characteristic sheath where leaf emerges.
Fruit: Glossy black seeds
Blooming: June-October
Habitat: Roadsides, waste areas, gardens and fields.

Comments: Introduced from Europe, and sometimes an invasive weed. The common name Lady's Thumb refers to the dark patch on the leaf, which supposedly resembles a lady's thumbprint. Called Redshank in Britain, possibly a reference to the pink stems. This and other smartweeds have recently been placed in the genus Persicaria by some authorities.

Where to find it: In cracks by Jefferson road, around the gardens by the lodge, and scattered in other disturbed areas.