Alstonia scholaris is a glabrous tree and grows up to 40 m (130 ft) tall. Its mature bark is grayish and its young branches are copiously marked with lenticels. The upper side of the leaves is glossy, while the underside is greyish. Leaves occur in whorls of three to ten; petioles are 1–3 cm (0.39–1.18 in); the leathery leaves are narrowly obovate to very narrowly spathulate, base cuneate, apex usually rounded; lateral veins occur in 25 to 50 pairs, at 80-90° to midvein. Cymes are dense and pubescent; peduncle is 4–7 cm (1.6–2.8 in) long. Pedicels are usually as long as or shorter than calyx. The corolla is white and tube-like, 6–10 mm (0.24–0.39 in); lobes are broadly ovate or broadly obovate, 2–4.5 mm (0.079–0.177 in), overlapping to the left. The ovaries are distinct and pubescent. The follicles are distinct and linear.