Annual highly variable seed weed germinating from spring to summer. Appears more frequently on well structured, moist, nutrient-rich sandy and loam soils.
Lady's thumb [Polygonum persicaria]
The cotyledons are elliptical, 10-15 mm long, with mostly reddish hypocotyl (stem) (Picture 1). Leaves are lanceolate (lance shaped)-pointed, with pressed-on hairs at the nerves and edge, and a dark spot frequently on the upper side (Picture 2). The membranous leaf sheath adhering to the stem is short-haired with distinctly long-ciliate at the edge. The pink flowers are comprised in roll-shaped, terminal and axial flower stalks (Picture 3). Each plant forms approx. 200-800 lenticular, pointed, smooth, glossy black seeds (Picture 4). Germination from 10 °C (Optimum: 35-40 °C).