noun Any plant whose foliage is covered with stinging, mildly poisonous hairs, causing an instant rash. Especially, most species of herb genus Urtica, stinging nettles: Most, but not all, subspecies of Urtica dioica (common nettle), Urtica incisa (Australian nettle); wood nettle (Laportea canadensis); bull nettles and spurge nettles (Cnidoscolus spp.): bull nettle, spurge nettle (Cnidoscolus stimulosus) Texas bull nettle (Cnidoscolus texanus), bull nettle (Cnidoscolus urens), nettle trees or tree nettles: Various species of the genus Dendrocnide: small-leaved nettle (Dendrocnide photinophylla). scratchbush (Urera baccifera) tree nettle (Urtica ferox); rock nettles (Eucnide spp.);
noun Especially, most species of herb genus Urtica, stinging nettles: Most, but not all, subspecies of Urtica dioica (common nettle), Urtica incisa (Australian nettle);
noun Most, but not all, subspecies of Urtica dioica (common nettle),