Description from Flora of China
Urtica himalayensis Kunth & Bouché; U. mairei H. Léveillé var. oblongifolia C. J. Chen; U. zayuensis C. J. Chen.
Herbs perennial, monoecious. Rhizomes woody. Stems branched, to 150 cm tall; stems, at least when old, and petioles sparsely armed with stinging and setulose hairs. Stipules dark brownish, interpetiolar, connate, oblong, 7-14 mm, herbaceous, with several ribs, appressed puberulent abaxially, apex obtuse; petiole 1.5-4.5 cm; leaf blade black or dark brownish when dry, narrowly ovate to lanceolate, 5-15 × 2-6 cm, herbaceous, 5-veined, lateral basal veins reaching middle, secondary veins 3 or 4 on each side, anastomosing before margin, adaxial surface glabrescent, abaxial surface setulose, base rounded or cordate, margin dentate or doubly denticulate, apex acuminate; cystoliths punctiform, rarely botuliform. Inflorescences containing male and female flowers, paniculate, with few short branches, longer than petioles. Male flowers subsessile, in bud ca. 1 mm; perianth lobes connate 1/2 of length, sparsely puberulent. Female flowers: perianth lobes connate at base, dorsal-ventral lobes broadly ovate, setulose, lateral lobes ovate, ca. 1/4 as long as dorsal ones. Achene light brownish, broadly ovoid, slightly compressed, ca. 1 mm, verrucose, invested by persistent perianth lobes. Fl. Jul-Aug, fr. Sep-Nov.
This species has been confused with Urtica parviflora, but that species has leaves broadly ovate, almost smooth when dried, with margins coarsely doubly dentate and stipules 2-cleft. Hara confused this species in SE Xizang and Yunnan with U. mairei, which has leaf margins doubly dentate (not lobed), stipules membranous, male inflorescences borne in distal axils, and achenes smooth.
Open or partly shady moist places in forests, thickets, along streams; 2400-2700 m. W Guangxi, SE Xizang, C and S Yunnan [Bhutan, N India, Nepal, Sikkim].