Alstonia scholaris
Asclepiadeae, 65. 1810.
Trees 2–20(–60) m. Leaves in whorls of 4–8; petiole 5–20(–25) mm, glabrous; blade narrowly elliptic to obovate, 5–17(–22) × 2–7(–8.5) cm, subcoriaceous, base cuneate, usually decurrent on petiole, less often acute or obtuse, margins somewhat revolute, apex obtuse, rounded, or retuse, surfaces glabrous or pubescent abaxially. Peduncles 0.5–5(–9) cm, pubescent or glabrate. Pedicels 0–2 mm, pubescent. Flowers: calyx lobes ovate, 1.5–2.4 mm, pubescent, ciliate; corolla white, yellow, or cream, eglandular-pubescent abaxially and adaxially, tube and throat together 7+ mm, tube 4–6 × 1–1.5 mm, throat 3–4 × 1.5–2 mm, lobes spreading, broadly ovate or suborbiculate, 3–5 × 2.5–4.5 mm. Follicles 20–40(–60) × 0.2–0.3 cm. Seeds 4–5(–7) mm. 2n = 44.
Phenology: Flowering fall; fruiting material not seen.
Habitat: Coastal hardwood hammocks.
Elevation: 0 m.
Distribution
Introduced; Fla., Asia, Pacific Islands, Australia.
Discussion
Alstonia scholaris is occasionally cultivated in southern Florida, where it may produce stems to 20 m in height and 1 m in diameter, and has become naturalized at a few sites in Broward, Miami-Dade, and Palm Beach counties.
M. S. Khyade et al. (2014) provided a lengthy list of the traditional medicinal uses of leaf, bark, and root extracts of Alstonia scholaris in India and document the antimicrobial, analgesic, anti-inflammatory, and possible anticancer potential of alkaloids isolated from the plant. In India, the wood was formerly used to make chalkboards (H. Drury 1873).
Selected References
None.