Spotted ladysthumb (redshank, Jesusplant, lady's thumb)
Polygonum persicaria (Persicaria maculosa)

Annual, seed-propagated weed with ramified taproot. Ocrea with small hairs emerging from the upper end. Characteristic purple splotch in the center of the leaf. The spot is not always present but typical. The perianth is somewhat variable in color. Cotyledons: Long-oval, rounded tip, dark green to reddish. Stems: Similar to Pale persicaria (Persicaria lapathifolium), up to 80 cm (31.49 inch) high. Leaves: Lanceolate, widest in the middle, upper surface often with dark spots, short-petiolate or sessile. Membranous tubes at the leaves' base often with short, appressed hairs. Visibly ciliate at the margin.