Distribution: Introduced sparsely in western Washington; distributed throughout much of North America except parts of the Midwest and Intermountain West.
Habitat: Moist, disturbed soil.
Flowers: June-July
Origin: Introduced from Europe
Growth Duration: Annual
Conservation Status: Not of concern
Pollination: Wind
Taprooted annual 1-5 dm. tall, more or less pubescent and strongly stinging-bristly.
Leaves opposite, petiolate, the blades elliptic to ovate or obovate, 1.5-4 cm. long, becoming larger upward, coarsely and deeply serrate; petioles on lower leaves are longer than their blades; stipules 2-3 mm. long.
Flowers in axillary clusters much shorter than the leaves, greenish, apetalous and imperfect; pistillate and staminate flowers mixed in the clusters, the pistillate larger, 1-2 mm. long, with 4 unequal calyx lobes and 1-celled pistil; staminate flowers with 4 stamens.
Achene
Publication: Sp. Pl. 2: 984. 1753. 1753.
PNW Herbaria: Specimen records of Urtica urens in the Consortium of Pacific Northwest Herbaria database.
WA Flora Checklist: Urtica urens checklist entry.
OregonFlora: Urtica urens information.
E-Flora BC: Urtica urens atlas page.
CalPhotos: Urtica urens photos.
USDA Plants: Urtica urens information.
