Boniodendron minus is a species of deciduous flowering shrub in the soapberry family (Sapindaceae) which is endemic to Vietnam. The trees are known to grow on limestone mountains.
- Family: Sapindaceae
- Genus: Boniodendron
- Scientific name: Boniodendron minusSynynonyms: Sinoradlkofera minor (Hemsl.) F.G. Mey. 1977., Koelreuteria minor Hemsl. 1900; Harpullia parviflora Lecomte, 1912; Boniodendron parviflorum (Lecomte) Gagnep. 1946.
- Vietnamese name: bông mộc
Trees: small, 2–15 m tall. Bark: dark brown, fissured; branches pubescent.
Leaves: fascicled at branch apices, paripinnate, 9–12 cm; petiole: 1–2 cm, slender, pubescent with axis; leaflets: 10–20; petiolules ca. 1 mm; blades: lanceolate or elliptic, 2–3(–4) × 1–1.5 cm, papery, glabrous except pubescent on midvein, base oblique, one side cuneate, other side rounded or obtuse, margin obtusely serrate, apex obtuse. Thyrses: terminal, rarely axillary, nearly as long as leaves, pubescent; branches: spreading.
Flowers: pale yellow to nearly white; buds globose, ca. 1.5 mm in diam. Pedicels: 2–3 mm, pubescent. Sepals: 5; upper 4 oblong, ca. 2.2 mm; lower 1 suborbicular, ca. 1.6 mm, white pubescent, margin ciliate. Petals: oblong, ca. 2.4 mm, pinnately veined, abaxially white pilose, adaxially glabrous. Stamens: 8; filaments ca. 4 mm. Ovary: 3-furrowed and ridged, hairy. Capsules: subglobose in outline, 3-winged, 1.8–2.3 cm (including wings) in diam., apex concave and with persistent style.
Seeds: ca. 4 mm in diam. Fl. May–Jun, fr. Jul–Aug.
In Vietnam, the bông mộc plant is cultivated as landscape trees in limestone mountains in Hạ Long Bay (Quảng Ninh province) to protect genetic and ecosystem diversity.