Pilea, with 600–715 species, is the largest genus in the plant family Urticaceae and one of the larger genera in the Urticales and eudicot rosids. It is distributed throughout the tropics, subtropics, and warm temperate regions (with the exception of Australia and New Zealand). The majority of species are succulent shade-loving herbs or shrubs, which are easily distinguished from other Urticaceae by the combination of opposite leaves (with rare exceptions) with a single ligulate intrapetiolar stipule in each leaf axil and cymose or paniculate inflorescences (again with rare exceptions).