The New Student's Reference Work/Nettle

Net′tle, species of Urtica, a genus containing about 30 species widely distributed. The best known nettle is U. dioica, known as the stinging nettle, which is a native of Europe and Asia, but has become extensively naturalized in the United States. It is densely beset with stinging hairs. At the base of each hair is a small gland secreting a poisonous fluid. It grows from two to three feet high and is common in waste places.