Homalium ceylanicum (Gardn.) Benth. is a tree in the genus Homalium (family Samydaceae).

Distribution and habitat

This plant is widely distributed in Hainan Province, covering Danzhou, Changjiang, Baisha, Dongfang, Qiongzhong, Lingshui, Wanning, Ledong, Baoting and Sanya.

It grows in dense forests or valleys 400-1,200 meters above sea level. It favors habitats with abundant light, and young branches are shade tolerant. It grows well in areas registering an average annual temperature of 22-24℃, an annual rainfall of 1,500-2,400 mm, and relative humidity of 75%-85%. Fertile, loose and well-drained soil is perfect for its growth, particularly deep, humus-rich soil on gentle slopes. It has a well-developed root system and is wind-resistant.

Morphological characteristics

This tree has gray-brown bark and is glabrous. Young trees have some corrugation. Leaves are leathery, glabrous, oblong to elliptic-oblong, rarely obovate, and 6-9(10) cm long and 2.5-4(5) cm wide. The apex changes from acute to acuminate, and the base is broad, acute or slightly obtuse. The margin is serrate-crenate to practically entire, with few obtuse apices. Midvein is flat adaxially and raised abaxially. Lateral veins are in 8-10 pairs and branched towards margins join superjacent veins. Petiole is glabrous. Inflorescence is axillary and racemose. Rachis is covered with short pubescence. Involucral pedicels are nearly glabrous. Flowers are mostly 5-6-merous, rarely in 4. Pedicels are very short, articulate at or above middle, and densely puberulous. Calyx tube is top-shaped, slightly appressed and densely pubescent. Sepals are linear-oblong, with apex acute, indumentum outside as for calyx tube, and margin densely ciliate. Petals are spatulate, whitish inside and pinkish outside when fresh, with both surfaces densely appressed with white pubescent and apex obtuse. Filaments are glabrous and longer than petals. Disk glands are truncate at apex and hairy. Ovary has filiform pubescence. Placentas appear in 4-6, each with 3-5 ovules. It blossoms between April and June.