Urtica dioica - Stinging Nettle

Stinging nettle is a very interesting plant. It looks like an ordinary, hairy weed with attractive little flowers, until touches it with bare hands. It gives a terrible sting, which is very painful. It is a perennial herb, 3-7 ft tall, dying down to the ground in winter. It has widely spreading rhizomes and stolons, which are bright yellow as are the roots. The soft green leaves are 3-15 cm long and are borne oppositely on an erect wiry green stem. The leaves have a strongly serrated margin, a heart-shaped base and a long-pointed tip with a terminal leaf tooth longer than adjacent laterals. Each leaf has a pair of elliptic stipules at the base. This is a distinguishing feature of the plant. It bears small greenish or brownish numerous flowers in dense clusters in leaf axils. The leaves and stems are very hairy with non-stinging hairs and also bear many stinging hairs, whose tips come off when touched, transforming the hair into a needle that will inject several chemicals: acetylcholine, histamine, 5-HT or serotonin, and possibly formic acid. This mixture of chemical compounds cause a painful sting. The pain and itching from a nettle sting can last from only a few minutes to as long as a week. In India, Stinging Nettle is found in the Himalayas, from Pakistan to SW China, at altitudes of 1000-2500 m. Flowering: August-September.