Description from Flora of China
Calophyllum nagassarium N. L. Burman; Mesua nagassarium (N. L. Burman) Kostermans.
Trees evergreen, 20-30 m tall. Trunk upright, buttressed at base; crown conic. Bark dark gray-brown, thin, fissured, lamellate, exuding aromatic white resin when wounded. Leaves always pendulous; petiole 5-8 mm; leaf blade reddish yellow when young, becoming dark green, abaxially usually glaucous, adaxially dark green and somewhat lucid, lanceolate or narrowly ovate-lanceolate to linear-lanceolate, (4-)6-10(-12) × (1-)2-4 cm, leathery; secondary veins numerous, obliquely parallel, slender and indistinct; tertiary veins and veinlets reticulate, ± visible under hand lens, base cuneate, apex acuminate or long acuminate to caudate. Pedicel 3-5 mm. Flowers bisexual, solitary, axillary, 5-8.5 cm in diam. Sepals (outer 2 slightly larger than inner 2) orbicular, convex, margin membranous and sometimes white ciliate. Petals white, obovate-cuneate, 3-3.5 cm. Stamens with filaments filiform, 1.5-2 cm; anthers golden-yellow, oblong. Ovary conic, ca. 1.5 cm; style 1-1.5 cm; stigma oblique. Fruit broadly ovoid or laterally depressed globose, ca. 3 × 2.5 cm, dry, longitudinally rugose, with stoutly pointed style at apex, usually dehiscent by 2 valves, with accrescent woody sepals and many persistent filaments at base; stalk robust, 0.8-1.2 cm. Seeds 1-4, ± irregular in shape; coat brown, fragile. Fl. Mar-May, fr. Aug-Oct. 2n = 32.
The seeds yield up to 79% oil, which is inedible but is used industrially. The wood is very hard. The tree is a handsome ornamental.
Usually cultivated, escaped and locally naturalized in SW Yunnan (Gengma: Mengding); 500-600 m. Guangdong (Xinyi), Guangxi (Rongxian, Tengxian), S, SW, and W Yunnan [Bangladesh, India, ?Indonesia (Java), Malaysia, Sri Lanka, Thailand].