Polygonum persicaria

Spotted Ladysthumb

Botanical description: Ladysthumb is quite an ornamental annual plant, exhibiting its relationship to the showy bistorts and persicarias intentionally grown for their flowers. Long since naturalized in North America from origins in Eurasia, Polygonum persicaria finds its way into garden plots, filling the bare ground between cultivated selections. Often in a small colony, it’s found growing along the length of a street between the granite curb and concrete sidewalk making it a contributor in the reduction of the first flush of stormwater flow. Plants can grow to two feet tall, but have a tendency to flop over, scrambling along the ground, bending at its characteristic swollen stem nodes. Leaves are often marked with a dark chevron, found on other Polygonums. The diminutive but prolific pink spikes of flowers range in color from light pink to magenta. Individual flowers are so small, they appear to be apetalous but upon closer inspection, bear five small petals. Bloom initiates in the heat of July, continuing through September. The long flowering period results in the production of copious seed, 800-1500 per plant, ensuring future generations of seedlings. The tiny black seeds are dispersed when animals or wind move stalks, shaking the seeds free.