22. Hancea Seemann, Bot. Voy. Herald. 409. 1857.
粗毛野桐属 cu mao ye tong shu
Authors: Huaxing Qiu & Michael G. Gilbert
Shrubs or trees, monoecious or dioecious; indumentum of simple hairs and gland-tipped hairs or sessile peltate-stellate hairs with central cells. Leaves [alternate or] opposite; stipules present, sometimes interpetiolar; leaf blade simple, base not glandular, margin entire, pinnately or palmately 3-veined. Inflorescences terminal or axillary, sometimes ramiflorous, [branched or] unbranched, male flowers 1-3 per bract, female 1 per bract. Male flowers: sepals 2-4, valvate; petals absent; disk absent; anthers 2-locular, extrorse, longitudinally dehiscent; pistillode absent. Female flower: sepals (3 or)4-6(or 7), imbricate or valvate; petals absent; disk absent; ovary [3-locular] with 1 ovule per locule; styles short; stigmas erect, adaxially shortly papillose. Fruit a capsule, spiny, spines sometimes gland-tipped. Seeds ± globose, 3-angled, without aril or carunculate.
About 17 species: Madagascar, Mascarenes, S China to Malaysia, Indonesia to New Guinea; one species in China.
Both morphological and molecular analyses (Slik & Welzen, Blumea 46: 3-66. 2001; Sierra et al., Blumea 51: 519-540. 2006; Sierra et al., Blumea 52: 361-366. 2007) have demonstrated that Hancea (as Cordemoya) is sister to Mallotus and Macaranga. There are no easy characters to reliably separate the genus as a whole from Mallotus, mostly because of convergence with aberrant species within Mallotus. The most reliable characters are pollen morphology and the very characteristic indumentum, lacking stellate hairs and glandular scales but with gland-tipped hairs or sessile stellate scales with central cells. In practice, the easiest character is the absence of obvious glands on the adaxial leaf surface in Hancea, which are always present in the Chinese species of Mallotus.