Sideroxylon rostrata Merrill, Philipp. J. Sci. 21: 351. 1922.

Trees 10--20 m tall. Branchlets terete to compressed apically, rust colored sericeous when young, glabrescent. Petiole 0.8--1.5 cm, rust colored sericeous, glabrescent; leaf blade elliptic, ovate, or obovate, 6--15 X 3--6 cm, almost leathery, both surfaces yellowish rust colored lanate when young, glabrescent and shiny or rust colored tomentose along veins when mature, base cuneate, apex obtuse to acuminate, lateral veins 9--13 pairs. Flowers white. Pedicel 6--10 mm, rust colored tomentose, glabrescent. Sepals ovate-lanceolate, 4--5.5 X 2--3 mm, both surfaces white appressed tomentose, margin membranous. Corolla glabrous. Staminodes broadly triangular. Ovary ovoid, 2--3 mm, white sericeous. Style terete, 0.9--1.1 cm. Fruit black, oliviform, 2--4 X 1.4--2.2 cm, base with persistent calyx, apex rostrate, pale yellow pubescent, pericarp woody, 1- or 2-seeded. Seeds oblong to ellipsoid, 2--3 X 0.8--1.5 cm, shiny yellowish brown, scar oblong and as long as seed. Fl. Jan-Feb.

No flowering specimens have been seen by the authors. The description of flowers is based on P. Royen (Blumea 8: 213. 1957.).

Xantolis boniana var. boniana occurs in Laos and Vietnam.

* Forests in ravines; 2000--2400 m. Hainan.