23. Trevia Linnaeus, Sp. Pl. 2: 1193. 1753.
滑桃树属 hua tao shu shu
Authors: Huaxing Qiu & Michael G. Gilbert
Trees; indumentum of simple or tufted hairs, sometimes with glandular hairs. Leaves opposite, entire, 3-5-plinerved; stipules 2. Inflorescences axillary, racemose. Plants dioecious. Inflorescence axillary, unbranched, male flowers 2 or 3 per bract. Male flowers: calyx closed in bud, valvate, 3-5-partite, reflexed; petals absent; disk absent; stamens 75-95; filaments free; anthers dorsifixed, 2-locular, connective sometimes widened; pistillode absent. Female inflorescence much shorter, 1-4-flowered. Female flowers: calyx 2-4-lobed, caducous; petals absent; disk absent; ovary 2-4-locular; ovules 1 per locule; styles 2-4, long, entire, conspicuously papillose. Fruit a drupe, indehiscent; endocarp crustaceous. Seeds ovoid; testa hard.
One, possibly two, species: S and SE Asia; one species in China.
The genus name is most often given as "Trewia" but this is merely an orthographical variant of the original "Trevia" and there is no justification for its use without formal conservation.
Kulju et al. (Blumea 52: 115-136. 2007) showed that Trevia is embedded within Mallotus, from which it differs only by the indehiscent fruit, and they transferred it to that genus, along with T. polycarpa Bentham, which they regarded as distinct. However, the name Trevia (1753) has priority over Mallotus (1790). For the sake of nomenclatural continuity, Mallotus should be formally conserved against Trevia because the former name is better known and has traditionally been applied to a much larger genus than the latter. The alternative would be many new combinations in Trevia. We are maintaining here the name Mallotus, which applies to a very easily recognized entity, until this nomenclatural issue is resolved.