Saptaparni Tree

Alstonia scholaris, commonly called blackboard tree, scholar tree, milkwood or devil's tree in English is an evergreen tropical tree in the dogbane family (Apocynaceae). It is native to southern China, tropical Asia (mainly the Indian subcontinent and Southeast Asia) and Australasia, where it is a common ornamental plant. It is a toxic plant, but is used traditionally for myriad diseases and complaints. It is called 'Saptaparna' in India and is the sacred tree of the 2nd Jain tirthankar Ajitnatha.

Description

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. A unique feature of this tree is that in some places, such as New Guinea, the trunk is three-sided (i.e. it is triangular in cross-section). The upper side of the leaves are glossy, while the underside is greyish Leaves occur in whorls of three to ten, with petioles 1–3 cm (0.4–1 in) long. The leathery leaves are narrowly obovate to very narrowly spathulate, with a cuneate base, and the apex is usually rounded and up to 23 cm (9.1 in) long by 8 cm (3.1 in) in width. Lateral veins occur in 25 to 50 pairs, at 80–90° to midvein. The cymes are dense and pubescent. Each peduncle is 4–7 cm (2–3 in) long. Pedicels are usually as long as or shorter than calyx. The corolla is white and tube-like, 6–10 mm (0.2–0.4 in) long. The lobes are broadly ovate or broadly obovate, 2–4.5 mm (0.08–0.2 in), overlapping to the left. The ovaries are distinct and pubescent. The follicles are distinct and linear.

Flowers bloom in the month of October. The flowers are very fragrant and similar to the flower of Cestrum nocturnum. Seeds of A. scholaris are oblong, with ciliated margins, and end with tufts of hairs 1.5–2 cm (0.6–0.8 in) long. The bark is almost odorless and very bitter, with abundant bitter and milky sap.