An annual erect herb 20-80 cm tall, stinging hairs scattered; stem branched, flexuous, furrowed; leaves 3-10 x 2-7 cm, ovate, acuminate at apex, subcordate, truncate or cuneate at base, crenate or serrate, sparsely covered with stinging hairs; petioles very long, slender; stipules linear, bifid; flowers in cymes, spikes or panicles, much aggregated, longer than the petiole, about 30 cm long, branched, branches often recurved; male flower minute, tepals 4, ovate, lanceolate, sepaloid, green or greenish white, imbricate, pubescent outside; stamens 4-5, reflexed bud; pistallode clavate or globose; female flowers with perianth campanulate or shortly 4 lobed, toothed, stipitate, keeled on one side, keels decurrent on the stipes, reflexed; ovary oblique, 1-celled, ovule erect, style obliquely linear or hooked at length with 2 basal arms; achenes ovoid, compressed, exserted, membranous; seeds minute, exalbuminous.