nettle

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.);

Loosely, anything which causes a similarly stinging rash, such as a jellyfish or sea nettle.

Certain non-stinging plants, mostly in the family Lamiaceae, that resemble the species of Urtica.

dead nettles, dumb nettles (Lamium spp.), particularly Lamium album, white nettle;

false nettles (Boehmeria spp., family Urticaceae);

flame nettles or painted nettles (Coleus spp.);

hedge nettles (Stachys spp.);

hemp nettles (Galeopsis spp.);

horse nettle Agastache urticifolia,

nilgiri nettles, Himalayan giant nettles (Girardinia diversifolia, family Urticaceae spp.).

Certain plants that have spines or prickles.

ball nettle (Solanum carolinense);

bull nettle, silver-leaf nettle, white horse-nettle (Solanum elaeagnifolium);

western horse-nettle, robust horse-nettle (Solanum dimidiatum);

horse-nettle (Solanum rostratum);

hackberries (Celtis spp.).

Of the nettle plant and similar physical causes, to sting, causing a rash in someone.

(figurative) To pique, irritate, vex or provoke.