Common: Common Nettle, Stinging Nettle
Most of US except S Florida
Nettle is a perennial herbaceous plant that forms colonies on floodplains, riverbanks, and other moist places, and introduced populations complement native ones. The plants may reach 6 feet in height but are usually shorter. It has opposite-toothed leaves that range from about 2 to 6 inches in length and almost half as wide. Most parts of the plant bear hairs that release histamine, formic acid, and other irritating compounds, causing an immediate but usually fairly brief stinging sensation upon contact with skin or mucus membranes. Nettle has found widespread use as an herbal medicine. As indicated by the species name, male and female flowers are found on different plants. Blooming may begin in late May and continue as late as October, depending on strain and location. Pollination is by wind, and reproduction is both by seed and underground rhizomes.