Rumex acetosella is a perennial herb to 40 cm tall; extensively colonial from thin roots, stems slender, branching, often reddish; stipule (ocrea) membranous sleeve-like around stem above leaf stalk (Flora of North America 1993+).
Leaves alternate, arrow shaped, base with narrow, divergent lobes to 1.2 cm long, long central lobe lance-shaped; sour, edible, contains oxalic acid.
Flowers greenish to reddish, tiny, sexes on different plants (dioecious), 6 petals (tepals) 3 inner and 3 outer, flower stalk jointed at top; inflorescence up to half the height of the plant, a branching cluster of spikes; blooming April- Aug., mostly June (Hough 1983).
Fruit dry, one-seeded 0.15 cm; fruiting June-Oct. (Hough 1983). Seeds eaten by many birds esp. ground feeders and by small mammals, plants eaten by rabbits and some birds (Martin et al. 1951).
Wetland status: UPL.
Frequency in NYC: Occasional.
Habitat: An agricultural weed. Acid soil, open areas, lawns, roadsides, fill. Intolerant of shade.