Description from Flora of China
Herbs perennial or shrubs, stellate. Leaves alternate; leaf blade orbicular or ovate, palmately lobed or sinuate, with 1 or more prominent foliar nectaries on abaxial surface. Flowers solitary or nearly fascicled, rarely racemelike, axillary or rarely aggregated on twig tips. Epicalyx campanulate, 5-lobed. Calyx 5-parted. Petals 5, stellate puberulent abaxially. Staminal column truncate or slightly incised; anthers numerous, on outside of staminal column only, nearly sessile. Ovary 5-loculed; ovule 1 per locule; style branches 10, reflexed; stigma discoid, apically ciliate. Fruit a schizocarp, subglobose; mericarps 5, ovoid, usually with spines, these each with a cluster of short barbs at tips. Seed 1, obovoid-trigonous or reniform, glabrous.
Some authorities have restricted Urena to the taxa with barb-tipped setae, sometimes treating these as a single, very variable, pantropical species, and placed other species, including U. repanda, in Pavonia. Some species of Triumfetta (Tiliaceae s.l.) are superficially rather similar and have been confused with this genus.
About six species: in tropical and subtropical regions; three species (one endemic) in China.