Urtica urens

Herbs, annual, with taproot, 1-8 dm. Stems simple or branched, erect. Leaf blades elliptic to broadly elliptic, widest near middle, 1.8-9 × 1.2-4.5 cm, base cuneate, margins coarsely serrate, serrations often with lateral lobes, apex acute; cystoliths rounded. Inflorescences spikelike or paniculate. Flowers unisexual, staminate and pistillate in same inflorescence, subsessile to short-pedunculate. Pistillate flowers: outer tepals ovate, 0.5-0.7 mm, inner tepals broadly ovate, 0.6-0.9 × 1.2-1.4 mm. Achenes ovoid, 1.5-1.8 × 1.1-1.3 mm. 2n = 24, 26.

Phenology: Flowering spring–summer.
Habitat: Waste places, roadsides, pastures, barnyards, cultivated fields, rich woodlands
Elevation: 0-700 m

Introduced; Greenland, St. Pierre and Miquelon, Alta., B.C., Man., N.B., Nfld. and Labr. (Nfld.), N.S., Ont., P.E.I., Que., Sask., Yukon, Ala., Alaska, Ariz., Calif., Conn., Fla., Ill., Iowa, Maine, Mass., Mich., Mo., Nev., N.H., N.Mex., N.Y., Okla., Oreg., Pa., R.I., S.C., Tex., Vt., Wash., Eurasia.

Discussion

Within the flora, Urtica urens is most abundant in California and in eastern Canada. The Shuswap used it medicinally for sweatbaths and for pain from rheumatism (D. E. Moerman 1986).

Selected References

None.

Lower Taxa