1. Excentrodendron tonkinense (A. Chevalier) Hung T. Chang & R. H. Miao, Acta Sci. Nat. Univ. Sunyatseni. 17(3): 23. 1978.
蚬木 xian mu
Pentace tonkinensis A. Chevalier, Bull. Écon, Indochine, n.s., 20: 803. 1918; Burretiodendron hsienmu Chun & F. C. How; B. tonkinense (A. Chevalier) Kostermans; Excentrodendron hsienmu (Chun & F. C. How) Hung T. Chang & R. H. Miao; E. rhombifolium Hung T. Chang & R. H. Miao.
Trees to 40 m. Petiole 3.5-6.5(-10) cm; leaf blade green, orbicular-ovate or elliptic-ovate, 8-14(-18) × 5-8(-12) cm, leathery, glossy, abaxially yellow-brown fascicled hairy in vein axils, lateral basal veins to 1/2 as long as blade, 10-15 mm from margin, each with 4 or 5 secondary veins, base rounded, apex acuminate or caudate-acuminate. Male inflorescences paniculate, 7-13-flowered, 5-9 cm; female inflorescences racemelike, 1-3-flowered. Flowers unisexual. Pedicel not articulate. Sepals oblong-lanceolate, 1-1.5 cm, abaxially brown stellate puberulent, adaxially glabrous, without glands or a few inner petals with 2 globose glands. Petals broadly obovate to spatulate, 8-9 × 5-6 mm, base obviously clawed. Stamens 25-35; filaments 4-6 mm; anthers ca. 3 mm. Female flowers unknown. Capsule
ellipsoid, 2-3 cm.
Evergreen forests on limestone. Guangxi, SE Yunnan [Vietnam].
Excentrodendron tonkinense (as Burretiodendron hsienmu) is included in the IUCN Red List as "Vulnerable (B1+2c)." The wood is very hard and is prized for making chopping boards.