10. Polygonum plebeium R. Brown, Prodr. 420. 1810.
Plants bluish green, homo-phyllous. Stems prostrate, much-branched from base, not wiry, 10-40 cm, papillose-scabridulous. Leaves: ocrea 1-veined, 2.5-3 mm, proximal part cylindric, distal part laciniate; petiole 0-1 mm; blade bluish green, narrowly elliptic or oblanceolate, 5-16 × 1-4 mm, margins flat, apex obtuse or acute, papillose-scabridulous; stem leaves 1-1.5(-2) times longer than adjacent branch leaves, distal leaves overtopping flowers. Inflorescences axillary; cymes uniformly distributed, 3-6-flowered. Pedicels exserted from ocreae, 3-5 mm. Flowers closed; perianth 1-1.5 mm; tube 12-27% of perianth length; tepals overlapping, green with white or pink margins, petaloid, not keeled, elliptic, cucullate; midveins unbranched, thickened; stamens 5. Achenes enclosed in perianth, black-brown, broadly ovate, 2-3-gonous, 1.5-2 mm, faces subequal, apex not beaked, edges concave, shiny, smooth; late-season achenes common, 2-4 mm. 2n = 20.
Flowering May-Oct. Disturbed sites; 50-500 m; introduced; Idaho; e Africa; s Asia; Australia.