Polygonum aviculare

Decumbent or prostrate annual, to c. 1.2 m diam. Ochreas 4–12 mm long, soon disintegrating. Lower leaves lanceolate to narrowly elliptic, 20–50 mm long, 5–18 mm wide, persisting until well after anthesis, margins flat or undulate, lateral veins obvious; leaves of lateral branches smaller than those of main stem(s). Flowers 1–5 in axillary clusters; perianth 2.5–3.5 mm long, the segments united for c. one-third their length, greenish with pink or white margins. Fruiting perianth not or barely enlarged. Nut with 3 more or less equal flat or concave faces, 2–3 mm long, dark brown, minutely roughened. Flowers mostly Dec.–May.