16. Disepalum J. D. Hooker, Trans. Linn. Soc. London. 23: 156. 1860.
异萼花属 yi e hua shu
Authors: Bingtao Li & Michael G. Gilbert
Trees or shrubs, indument of simple or stellate hairs. Petiole often short to absent. Inflorescences terminal or sometimes leaf-opposed, 1-3-flowered. Pedicel slender, pendent, without bracteoles. Sepals [2 or]3, relatively large, valvate, free, eventually ± reflexed. Petals [4-]6, in [1 or]2 whorls, ± equal, free [or united into cup, sometimes adnate to torus], sometimes imbricate at tips. Torus usually much wider than high, enlarged in fruit. Stamens many; connective depressed-globose, wider than anther locules. Carpels many; ovules (1 or)2(or 3), lateral. Styles oblong, often hairy at apex. Fruit apocarpous; monocarps usually many, each on long stipelike carpophore articulate at apex, usually ± ellipsoid, fleshy. Seeds usually 2, shiny chestnut-brown, ellipsoid or flattened-ellipsoid.
Nine species: China, Indonesia, Laos, Malaysia, Vietnam; two species in China.
The fruit of Disepalum are very distinct because of the different origin of the carpophores bearing the monocarps. In most members of the Annonaceae the monocarps are borne on stipes formed by extension of the monocarps themselves. In Disepalum the monocarps are borne on carpophores derived from the torus that differ in color and texture from the monocarps and are abruptly separated from them by an articulation at the apex. The Chinese species had previously been placed in Polyalthia or placed in their own genus Enicosanthellum. Disepalum s.s. has extremely distinctive flowers, but Johnson (Brittonia 41: 356-378. 1989) argues that the very unusual fruit make a good case for including Enicosanthellum within Disepalum.