Any of several plants of the genus Urtica, which have long, toothed leaves and myriad hairlike fibers that contain formic acid, which irritates the skin on contact. Urtica dioica is the nettle most commonly used culinarily. Nettles must be cooked to destroy their stinging effect, and only the young shoots and leaf tops are used.
From The Food Lover's Companion, Fourth edition by Sharon Tyler Herbst and Ron Herbst. Copyright © 2007, 2001, 1995, 1990 by Barron's Educational Series, Inc.