Published online by Cambridge University Press: 12 June 2017
Nettles belong to the genus Urtica, in the Urticaceae, which includes about 30 species of herbs, shrubs, and trees of world-wide distribution (3, 12). These species have recognizable similarities but vary considerably in height - from 0.3 to 0.66 m to 2.6 or 3 m tall (15). Nettles have a peculiar notoriety. As the 17th century herbalist Nicholas Culpeper (5) wrote, “Nettles are so well known, that they need no description, they may be found by feeling for them in the darkest night.”