Shrubs or small trees, 1.5-6 m tall. Branchlets, petioles, and inflorescences densely brownish floccose-tomentose or brownish or yellowish pulveraceous tomentose. Stipules subulate, 5-15 mm; petiole 5-20 cm; leaf blade suborbicular or broadly ovate, often tricuspidate or shortly and acutely 1- or 2-lobed, 8-35 × 6-28 cm, papery, adaxially stellate-villous along nerves, abaxially stellate-tomentose, scattered yellow glandular-scaly, base rounded, broadly peltate, with up to 4 basal glands, margin repand-denticulate, apex acuminate; basal veins 5-7. Male inflorescences terminal, branched or unbranched, 15-34 cm; bracts subulate, 5-7 mm. Male flowers 3-5-fascicled; pedicel 3-4 mm; calyx lobes 4 or 5, oblong, 3-3.5 mm, stellate-pubescent; stamens 75-85. Female inflorescences branched or unbranched; peduncle stout; infructescence erect, 10-20 cm; bracts subulate, 4-5 mm. Female flowers: pedicel 2-3 mm; calyx 4- or 5-lobed, 4-5 mm, tomentose; ovary 3-5-locular, densely setose, tomentose; style 3-4 mm, plumose. Fruiting pedicel 5-30 mm; capsule subglobose, 12-20 mm in diam., densely stellate-tomentose and softly spiny, forming a continuous uniform layer, spines linear, 6-7 mm. Seeds ovoid, ca. 5 mm, black, verruculose. Fl. Apr-May, fr. Sep-Oct.

The concept of Mallotus barbatus is sometimes extended to include M. lotingensis (see Govaerts et al., World Checkl. Euphorbiaceae: http://www.kew.org/wcsp/home.do). Mallotus luchenensis is also closely related. This complex needs more detailed study.

Mountain slopes or valleys, forests, thickets, limestone hills, roadsides, often in clearings; 200-1300 m. Guangdong, Guangxi, Guizhou, W Hubei, Hunan, Sichuan, Yunnan [India, Malaysia, Myanmar, Thailand, Vietnam].