Common Name: Stinging Nettle
Description: Erect annual or perennial herbs covered with rigid stinging hairs.
Leaves opposite, toothed, usually 3–5-veined at base, petiolate.
Inflorescence axillary, paniculate to cymose, often drooping. Flowers unisexual, small, green or white. Perianth deeply 4-lobed, the lobes equal in the male flowers, the 2 inner lobes enlarged in the female flowers. Stamens 4. Stigmas ± sessile.
Achenes compressed, enclosed in the persistent perianth.
Distribution and occurrence: World: 50 species, mostly northern temperate, some southern temperate, a few in tropical regions. Australia: 3 species (1 species native, 2 species naturalized), all States.
Text by G. J. Harden Taxon concept:
| Key to the species | |
1 | Leaves and stems distinctly pubescent between the longer, scattered stinging hairs; petiole often less than half as long as the lamina; lamina dark green on both surfaces | Urtica dioica |
| Leaves and stems more or less glabrous between the stinging hairs; petiole usually more than half as long as the lamina; lamina dark green above, paler green below | 2 |
2 | Leaves with lamina mostly 1–5 cm long, ovate to elliptic; annual; inflorescence usually branched and shorter than the petiole | Urtica urens |
| Leaves with lamina mostly 5–12 cm long, usually lanceolate to narrow-ovate, sometimes to broad-ovate; perennial; inflorescence mostly unbranched and often much longer than the petiole Back to 1 | Urtica incisa |
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