Rumex cordatus, commonly known in Afrikaans as maksuring (tame sorrel) or tongblaar (tongue leaf) and botanically previously as R. sarcorrhizus, is an erect perennial, sometimes an annual that grows from a tuber, reaching 50 cm in height. The thickish stem is longitudinally lined or ridged.
The leaves mainly form a basal tuft, the few stem-leaves smaller and alternate. The leaf-shape is ovate, roundly lobed at the base and the margins entire. The leaves are up to 9 cm long.
The small red flowers grow in whorls in a raceme. The perianth segments of the individual flower grow in two whorls of three. There are six stamens and a three-angled ovary, enclosed in the persistent perianth during the fruiting stage. Flowering happens late in winter to mid-spring. The fruits are red.
The species distribution is in Namaqualand in the Northern Cape, the Karoo in the Western Cape and Eastern Cape to KwaZulu-Natal.
The plants grow widespread on sandy flats and lower slopes among diverse vegetation. The species is not considered to be threatened in its habitat early in the twenty first century.
Only about 18 of the 200 Rumex species occur in southern Africa (Le Roux, et al, 2005; Leistner, (Ed.), 2000; Bond and Goldblatt, 1984; iNaturalist; http://redlist.sanbi.org).