Rumex L.

Perennial or sometimes annual herbs, occasionally climbing, rarely shrubby; roots often thick. Lvs radical or cauline, very variable, mostly longer than wide, commonly bullate and undulate, sometimes hastate; ochreae ± tubular. Fls in simple or branched racemes or spikes, often strongly protandrous, often whorled, green, often turning reddish later, mostly ☿, sometimes unisexual (plants monoecious or dioecious). Pedicels jointed, usually deflexed at fruiting. Perianth segments 6, ± free; outer 3 remaining small and thin and often reflexing; inner 3 (fr. valves) enlarging in fr., often becoming hard, prominently veined, not keeled, sometimes with marginal teeth, sometimes with dorsal tubercles, these forming enlarged corky areas on the midrib. Stamens 6, in 2 whorls. Styles 3, very short; stigmas usually strongly lobed and mostly penicillate. Fr. a trigonous nut, with surrounding perianth segments sometimes spiny.

[From: Webb et al. (1988) Flora of New Zealand. Volume 4.]