2. Calophyllum membranaceum Gardner & Champion, Hooker’s J. Bot. Kew Gard. Misc. 1: 309. 1849.
薄叶红厚壳 bao ye hong hou ke
Calophyllum spectabile Hooker & Arnott (1833), not Willdenow (1811).
Shrubs to small trees, 1-5 m tall. Young shoots tetragonous, narrowly winged. Petiole 6-10 mm; leaf blade lucid and opaque-brown on both surfaces when dry, oblong or oblong-lanceolate, 6-12 × 1.5-3.5 cm, thinly leathery, midvein raised on both surfaces, base cuneate, margin revolute, apex acute, acuminate, or caudate-acuminate. Cyme axillary and terminating short axillary shoots, (1-)3(-5)-flowered, 2.5-3 cm, puberulous. Pedicels 5-8 mm, glabrous. Flowers reddish white. Sepals 4; outer 2: suborbicular, ca. 4 mm; inner 2: obovate, ca. 8 mm. Petals 4, obovate, equal in size, ca. 8 mm. Ovary ovoid; stigma subulate. Mature fruit yellow, ovoid-oblong, 1.2-2 cm, apiculate. Fl. Mar-May, fr. Aug-Oct(-Dec).
Dense or sparse forests on hills; (200-)600-1000 m. S Guangdong, S Guangxi (coast), Hainan [Vietnam].
The roots and leaves are used as medicine for traumatic injuries or rheumatoid arthritis.