Annual or perennial, erect or climbing herbs (rarely shrublets), dioecious or polygamous, rarely monoecious. Leaves alternate, petiolate, not articulate; ochreas short, tubular, brownish, membranous, entire but soon disintegrating, not ciliate at apex. Flowers clustered in racemes or racemose panicles; perianth segments 6, sepaloid, the inner 3 enlarging and becoming membranous at maturity, much exceeding fruit; stamens 6; stigmas 3, each flattened, 2-branched and delicately fringed. Nut triquetrous, remaining enclosed by the fruiting perianth.
About 30 species from Eurasia and Africa; 2 naturalised in Australia.
Sometimes included in an expanded Rumex (e.g. Schuster et al. 2015).
Schuster, 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.