Wood nettle, or stinging nettle, is a perennial nonwoody plant with a single, slightly zigzag stem and armed with stinging hairs. Flowers are small, light green, in small clusters arranged in panicles, arising from the leaf axils; clusters of staminate flowers are positioned below the pistillate ones. Blooms May–August. Leaves are alternate, long petioled, broadly ovate, pointed, coarsely toothed. Young leaves are usually wrinkled and hairy. Thin stipules are present at leaf bases. Tiny white dots (cystoliths) containing calcium carbonate crystals appear on stems and leaves. Stems and leaves are covered with hairs containing caustic irritants.
Similar species: There are 6 other species in the nettle family in Missouri. The others in the genus Urtica (including U. dioica, tall nettle) have opposite, not alternate leaves. False nettle (Boehmeria cylindrica) has alternate, entire leaves and sparse to dense, nonstinging hairs. Clearweed (Pilea pumila) is a glabrous (smooth) plant with opposite, translucent leaves.
Habitat and Conservation
The stinging hairs act like tiny syringes, injecting alkaloids and other toxins upon contact. The skin reacts with histamines, and a burning, itching feeling results.
Oddly enough, if you use gloves and snippers to pick young shoots under 8 inches tall, and wash and cook them, nettles can be eaten as potherbs.
The famous Missouri botanist Julian Steyermark called this plant a great “nuisance to anyone tramping the wooded valleys in summer and autumn,” especially since it grows in large, thick stands. But he pointed out that it pales in comparison to some of the stinging plants he endured as he did research in the tropics.
A variety of insects eat the leaves, including the larvae of comma, question mark, and red admiral butterflies.
Deer sometimes eat the foliage.
Many animals take shelter in the jungle-like tangles of dense stands.
Plants that grow along banks of rivers and streams help prevent erosion.