Description from Flora of China
Polyalthia sect. Goniothalamus Blume, Fl. Javae, Annonaceae, 71, 79. 1830.
Trees or erect shrubs. Petiole short; leaf blade large, secondary veins arcuately looped near margin. Inflorescences axillary or extra-axillary, 1-flowered or several flowers in fascicles. Pedicel bracteolate at base. Sepals 3, valvate. Petals 6, in 2 whorls, with each whorl valvate; outer petals flat, thick; inner petals small, base shortly clawed, apex forming a cap. Stamens many; anther locules linear or oblong, extrorse; connectives oblong or clavate, 3-angular, apex truncate or rarely rounded. Carpels many; ovules 1-10 per carpel, ± basal; styles elongate; stigmas entire or apex 2-lobed. Fruit apocarpous; monocarps subsessile to shortly stipitate, oblong-ellipsoid or ovoid. Seeds 1-10 per monocarp.
A record of Goniothalamus macrophyllus (Blume) J. D. Hooker & Thomson from the Flora area (X. L. Hou, http://www.abclunwen.com/ lunwen-free-387606/; accessed on 25 Nov 2010) was based on a misidentification of Polyalthia simiarum.
About 130-140 species: tropical and subtropical Asia; 11 species (five endemic) in China.
(Authors: Li Bingtao (李秉滔 Li Ping-tao); Michael G. Gilbert)