Alstonia
Asclepiadeae, 64. 1810. name conserved
Trees [shrubs]; latex milky. Stems erect, unarmed, glabrous [eglandular-pubescent]. Leaves persistent, whorled [opposite], petiolate; stipular colleters interpetiolar; laminar colleters absent. Inflorescences terminal, compound-cymose, pedunculate. Flowers: calycine colleters absent; corolla white, yellow, or cream, salverform, aestivation dextrorse [sinistrorse]; corolline corona absent; androecium and gynoecium not united into a gynostegium; stamens distinct, inserted at top of corolla tube; anthers not connivent, not adherent to stigma, connectives not appendiculate or enlarged, locules 4; pollen free, not massed into pollinia, translators absent; nectary annular. Fruits follicles, usually paired, pendulous, brown, slender, terete, surface striate, glabrous or pubescent. Seeds elliptic to oblong, flattened, marginally long-ciliate, not winged, not beaked, comose, not arillate. x = 11.
Distribution
Introduced; Florida, Asia, Africa, Indian Ocean Islands, Pacific Islands, Australia.
Discussion
Species ca. 43 (2 in the flora).
Selected References
None.
Lower Taxa
Key
1 | Leaves in whorls of 3 or 4; corolla tube and throat together to 6.5 mm; flowering winter–spring. | Alstonia macrophylla |
1 | Leaves in whorls of 4–8; corolla tube and throat together 7+ mm; flowering fall. | Alstonia scholaris |