Pilea


Pilea, with 600–715 species, is the largest genus of flowering plants in the nettle family Urticaceae, and one of the larger genera in the Urticales.
It is distributed throughout the tropics, subtropics, and warm temperate regions.
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 a single ligulate intrapetiolar stipule in each leaf axil and cymose or paniculate inflorescences.
Pilea is of little economic importance; six species have horticultural value, and one species is used in Chinese traditional medicine. The genus has attracted little monographic attention since Weddell, and the majority of taxonomic contributions have come from floristic treatments. To date, 787 species names have been published and estimates for the species number range from 250 to 1000. Based on previous floristic treatments, about 30% of the species from regions not yet covered by contemporary floristic treatments may be undescribed.
The genus name is derived from Latin pileus, "felt cap", because of the calyx covering the achene.

Species include

The fossil species †Pilea cantalensis was widely distributed in Europe and West Siberia during the Miocene and Pliocene. It is related to the East Asian Pilea mongolica and to the North American Pilea pumila.