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.
Plant: annual herb; Monoecious, erect, simple or branched, 10-75 cm tall Leaves: elliptic to widely elliptic, the blades 1.8-9 cm long, 1.2-4.5 cm wide; apex acute; base cuneate to widely cuneate; margins coarsely serrate, the serrations often with lateral lobes; cystoliths punctiform INFLORESCENCE: spikelike to paniculate, with both staminate and pistillate flowers, subsessile to short pedunculate Flowers: PISTILLATE FLOWERS with outer tepals ovate, 0.5-0.7 mm long; inner tepals widely ovate, 0.6-0.9 mm long; STAMINATE FLOWERS with 4 equal tepals, 4 stamens, and a rudimentary, cuplike ovary Fruit: FRUITS ovoid, 1.5-1.8 mm long, 1.1-1.3 mm broad Misc: Waste places, roadsides, cultivated fields; to ca. 600 m (2000 ft); spring-summer REFERENCES: Boufford, David E. 1992. Urticaceae. Ariz.-Nev. Acad. Sci. 26(1)2.
Taprooted annual, simple or branched, 2-5 dm, with numerous stinging hairs; lvs long-petioled, elliptic to broadly ovate and blunt or rounded in outline, deeply incised- serrate, the teeth triangular, acute, upper lvs usually larger than the lower; stipules oblong, 1-3 mm, fl-clusters oblong, often shorter than the petioles; achenes triangular, 1.5-2.5 נ1-1.5 mm; 2n=24, 26, 52. Native of Europe, widely distributed elsewhere as a weed, and occasionally found in our range. May-Sept.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.