4.
Urtica urens
Linnaeus, Sp. Pl. 2: 984. 1753.
Dog nettle, burning nettle
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. 2 n = 24, 26.
Flowering spring-summer. Waste places, roadsides, pastures, barnyards, cultivated fields, rich woodlands; 0-700 m; introduced; Greenland; St. Pierre and Miquelon; Alta., B.C., Man., N.B., 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.
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).
