Description from Flora of China
Boehmeria platyphylla D. Don var. tricuspis Hance, J. Bot. 12: 261. 1874; B. japonica Miquel var. platanifolia Maximowicz; B. maximowiczii Nakai & Satake; B. platanifolia Franchet & Savatier.
Subshrubs or herbs perennial, simple or few branched, 0.5-1.5 m tall; upper stems and branchlets densely pubescent. Dioecious or monoecious. Leaves opposite or rarely alternate, subequal in size; stipules lanceolate, 7-10 mm; petiole 1.5-6(-10) cm, densely pubescent; leaf blade dark green or black when dry, oblate to 5-angled or oblate to orbicular-ovate, often ovate in upper stems, 8-12(-18) × 7-14(-22) cm, papery, secondary veins 2 pairs along midvein, abaxial surface densely pubescent along veins and veinlets, adaxial surface roughish, densely strigose, base truncate, subcordate, or broadly cuneate, margin coarsely 8-12-dentate, teeth gradually larger distally, often biserrate apically, apex 3-cusped or lobed, tip serrulate. Glomerules on axillary spikelike flowering branches, male branches often branched, 8-17 cm; female spikes distal, unbranched or branched, 5.5-24 cm. Male flowers 4-merous, sessile; perianth lobes elliptic, ca. 1 mm, strigillose, connate at base. Fruiting perianth rhomboid-obovoid, compressed, ca. 1.2 mm, smooth, strigillose on shoulder, base cuneate or stipitate, apex with short neck, 2-toothed. Fl. Jul-Aug, fr. Sep-Oct.
The high-quality fibers are used to make cloth, paper, and ropes. The leaves are used as fodder and as traditional medicines to relieve internal fever.
Forest margins, thickets, along streams in hills and mountains; 500-1400 m. Anhui, Fujian, S Gansu, Guangdong, Guangxi, Guizhou, W Hebei, W Henan, Hubei, Hunan, Jiangsu, Jiangxi, Shaanxi, Shandong, Shanxi, Sichuan, Taiwan, SE Yunnan, Zhejiang [Japan, Korea].