Syzygium hainanense seeds are harvested in June. 海南蒲桃 hai nan pu tao. Trees, to 5 m tall. Branchlets brown when dry, terete; old branches grayish white. Petiole 1-1.5 cm; leaf blade elliptic, 8-11 × 3.5-5 cm, leathery, abaxially reddish brown when dry, adaxially brown and slightly glossy when dry, adaxially with numerous glands, secondary veins numerous, 1-1.5 mm apart, at an angle of 75°-80° from midvein, abaxially raised, and adaxially visible, intramarginal veins ca. 1 mm from margin, base broadly cuneate, apex acute and with a 1.5-2 cm cusp. Flowers not seen. Infructescence axillary, cymose. Fruit ellipsoid to obovoid, 1.2-1.5 × 0.8-0.9 cm; persistent calyx lobes ca. 0.5 × 4 mm. Seeds 2 per fruit, 6-7 × 6-7 mm.