4. Debregeasia longifolia (N. L. Burman) Weddell in Candolle, Prodr. 16(1): 235. 1869.
长叶水麻 chang ye shui ma
Urtica longifolia N. L. Burman, Fl. Indica, 197 [“297”]. 1768; Conocephalus niveus Wight; Debregeasia dichotoma (Blume) Weddell; D. libera Chien & C. J. Chen; D. velutina Gaudichaud-Beaupré; Morocarpus dichotomus (Blume) Blume; M. longifolius (N. L. Burman) Blume; M. velutinus Blume; Urtica angustata Blume; U. dichotoma Blume.
Shrubs or small trees 3-6 m tall, dioecious or monoecious. Branchlets slender, reddish or purplish brown; branchlets and petiole densely spreading hirtellous. Stipules oblong-lanceolate, 6-10 mm, 2-cleft in distal 1/3; petiole 1-4 cm; leaf blade adaxially dark green, oblong- or obovate-lanceolate, sometimes linear or narrowly ovate, 7-18(-23) × 1.5-5(-6.5) cm, papery, sometimes thinly so, 3-veined, lateral ones straight, reaching to middle, secondary veins 5-8(-10) on each side from basal 1/3, anastomosing at margin, abaxial surface thinly greenish gray or gray-white tomentose, densely hirtellous on veins, adaxial surface sparsely appressed strigose, sometimes rugose, base rounded or subcordate, rarely broadly cuneate, margin finely serrulate or denticulate throughout, apex acuminate. Inflorescences borne on current and previous years’ branches, 2-4-dichotomously branched, 1-2.5 cm; peduncle 0.3-3 cm, spreading hirtellous; glomerules globose, 3-4 mm in diam.; bracts triangular-ovate, ca. 1 mm, membranous. Male flowers shortly pedicellate, obovoid in bud, 1.2-1.5 mm in diam.; perianth lobes 4, broadly ovate, puberulent abaxially, connate at middle, apex acute; rudimentary ovary sessile, obovoid, ca. 0.5 mm. Female flowers sessile, obovoid, ca. 0.8 mm; perianth tube membranous, 4-denticulate at apex. Achene reddish or orange, ca. 1-1.5 mm, enclosed by fleshy perianth and adnate to it. Fl. Aug-Dec, fr. Sep-Feb.
Shady, moist places by streams, forests in mountain valleys; 500-3200 m. W Hubei, SE Gangsu, W Guangdong, Guangxi, Guizhou, S Shaanxi, Sichuan, S Xizang, Yunnan [E Bangladesh, Bhutan, Cambodia, India, Indonesia, Laos, Malaysia, N Myanmar, Nepal, Philippines, Sikkim, Sri Lanka, Thailand, Vietnam].
This species is very common in SW China; its morphology is variable, especially in leaf shape and petiole length. The plant fibers are of high quality.