9. Brachytome J. D. Hooker, Hooker’s Icon. Pl. 11: 70. 1871.
短萼齿木属 duan e chi mu shu
Authors: Tao Chen & Charlotte M. Taylor
Shrubs or small trees, dioecious or perhaps polygamo-dioecious, unarmed, often with some internodes reduced. Raphides absent. Leaves opposite or often appearing ternate due to reduced internodes and marked anisophylly grouping 2 leaves at 1 node plus a single leaf at another node, apparently without domatia; stipules persistent or deciduous after terminal 2-4 nodes, interpetiolar or shortly united around stem, triangular. Inflorescences pseudoaxillary, usually borne opposite a single leaf of an anisophyllous pair and appearing leaf-opposed or sometimes just above an undeveloped internode at an apparent 3-leaved node, cymose, few to several flowered, subsessile to pedunculate, bracteate. Flowers subsessile to pedicellate, unisexual or perhaps sometimes bisexual. Calyx limb cupular, 5-lobed or -dentate. Corolla white to cream or pale yellow, funnelform to tubular or subrotate, glabrous inside; lobes 5, convolute in bud. Stamens 5, inserted in corolla throat, exserted, with staminodes included; filaments short; anthers dorsifixed. Ovary 2-celled, ovules many in each cell on peltate axile placentas; stigma 2-lobed, grooved striate, partially exserted. Fruit red to orange, baccate, fleshy, globose to ellipsoid, smooth, with calyx limb persistent, often with fruit base and/or pedicels elongating into stipes; seeds numerous, small, cuneate to flattened, with testa reticulate; endosperm fleshy; embryo small, subterete.
About five species: Bangladesh, Cambodia, China, India, Malaysia, Myanmar, Vietnam; three species in China.
The morphology and branching of this genus were studied by Tirvengadum and Sastre (Bull. Mus. Natl. Hist. Nat., B, Adansonia 8: 257-296. 1986).
Brachytome was described as polygamo-dioecious in FRPS (71(1): 360. 1999), but this has not been reported by other sources; the genus was described as unisexual by Puff et al. (Rubiaceae of Thailand, 68. 2005).
