Description from Flora of China
Small trees or shrubs, 3-7 m tall. Branchlets densely ferruginous stellate-tomentose. Stipules filiform, 6-8 mm, stellate pubescent; petiole 5-15 cm, brown tomentose; leaf blade subovate-rotund or long ovate, 15-23 × 10-18 cm, often tricuspidate or shortly 1- or 2-lobed, papery, adaxially along nerves stellate-pubescent, abaxially densely white stellate-pubescent, scattered orange glandular-scaly, base rounded or obtuse, broadly peltate, with 4 basal glands, margin sparsely denticulate, apex acuminate or caudate; basal veins 7-9. Inflorescences terminal, branches few or absent, (10-)18-28 cm, brownish tomentose; bracts filiform, 8-10 mm. Male flowers 2- or 3-fascicled; pedicel 6-7 mm; calyx lobes 4 or 5, ovate, ca. 3 mm, pubescent; stamens 60-80. Female flowers: pedicel 4-6 mm; sepals 3-5, 4-5 mm, tomentulose; ovary tomentose; style 4, ca. 6 mm, plumose. Infructescence elongated, 10-27 cm. Fruiting pedicel 6-12 mm; capsule subglobose, ca. 20 mm in diam., densely white stellate-pubescent and softly spiny, forming a continuous uniform layer, spines linear, 7-8 mm. Seeds ellipsoid, ca. 6 mm, black. Fl. May-Sep, fr. Jun-Oct.
Mallotus luchenensis was treated as part of M. barbatus by S. M. Hwang (Acta Phytotax. Sin. 23: 295. 1985).
Mountain valleys or slopes, limestone hills, forests, thickets; 200-1300 m. Guangxi, Guizhou [N Vietnam].