Acetosella
Perennial herbs, dioecious or rarely polygamous. Leaves alternate, petiolate, not articulate, often largely basal; ochreas short, tubular, whitish, membranous, glabrous, entire or lacerate at apex, soon disintegrating. Flowers clustered, shortly pedicellate, in slender terminal panicles; perianth segments 6, sepaloid, the inner 3 segments of female flowers rapidly enlarging in fruit, but not or barely exceeding the nut; stamens 6; stigmas 3, peltately attached, fringed. Nut triquetrous, closely enclosed by the fruiting perianth.
4 species from Europe and western Asia, extending into Arctic regions; 1 naturalised in Australia.
Sometimes included in an expanded Rumex (e.g. Schuster et al. 2015).
Walsh, N.G. (1996). Polygonaceae. In: Walsh, N.G.; Entwisle, T.J., Flora of Victoria Vol. 3, Dicotyledons Winteraceae to Myrtaceae, pp. 272–295. Inkata Press, Melbourne.
SpinningSchuster, T.M.; Reveal, J.L.; Bayly, M.J.; Kron, K.A. (2015). An updated molecular phylogeny of Polygonoideae (Polygonaceae): Relationships of Oxygonum, Pteroxygonum, and Rumex, and a new circumscription of Koenigia.. Taxon 64(6): 1188–1208.