Urticaceae (nettle) family plants may be trees, shrubs or creepers but are most are small herbs. Leaves are generally unlobed, entire or toothed, and often have a covering of stinging hairs. Flowers are inconspicious, arranged in catkins or other clusters, and are usually monoecious or dioecious. There are over 2,500 species worldwide but just four in the UK (nettle, small nettle, pellitory-of-the-wall and mind-your-own-business), the latter naturalised.
