THE NETTLE FAMILY (Urticaceae)

This is a family of flowering plants that includes approximately 2600 species, grouped into 54 to 79 genera according to the database of the Royal Botanic Gardens, Kew. The family name comes from the genus Urtica (nettle), particularly important as food plants for certain species of moths and butterflies. Urticaceae can be found worldwide, apart from the polar regions.

Leaves are usually entire and bear stipules. Urticating (stinging) hairs are often present. Flowers are usually unisexual and tend to be small and difficult to see although the clusters, in spite of not being colourful, may be large and conspicuous. (Pollination is by wind, hence no need for colourful petals, the function of which is to attract insects). Most disperse their pollen when the stamens are mature when their filaments straighten explosively, a peculiar and conspicuously specialised mechanism.

(source: Wikipedia)