11. Canthium Lamarck, Encycl. 1: 602. 1785.
鱼骨木属 yu gu mu shu
Authors: Tao Chen, Charlotte M. Taylor & Henrik Lantz
Meyna Roxburgh ex Link.
Shrubs or small trees, sometimes dioecious, sometimes with short shoots, unarmed or sometimes with paired straight supra-axillary thorns. Raphides absent. Leaves opposite, with or without domatia; stipules persistent or caducous, interpetiolar, shortly united around stem, or fused to petiole bases, triangular, internally (i.e., adaxially) sometimes sericeous to pilose. Inflorescences axillary, cymose to fasciculate, few to several flowered, sessile to pedunculate, bracteate with bracts sometimes fused in calyculate pairs. Flowers subsessile to pedicellate, bisexual and monomorphic (Canthium s.s.) or sometimes unisexual. Calyx with ovary portion often subglobose to hemispherical; limb very short, truncate or 4- or 5-lobed. Corolla green to white or pale yellow, tubular, urceolate, or funnelform, with tube often constricted at top, inside variously pubescent but usually with ring of introrse hairs in tube; lobes 4 or 5, often long acuminate or aristate at apex, in bud valvate and often with apices held erect and pressed together forming apiculate projection, at anthesis notably reflexed. Stamens 4 or 5, inserted at corolla throat, partially to fully exserted; filaments short or reduced; anthers dorsifixed near base, elliptic to ovate, at anthesis reflexed. Ovary 2-5-celled, ovules 1 in each cell, pendulous from apical placenta; stigma included or exserted, capitate to cupular, entire to variously lobed, usually with style attachment recessed. Fruit brown, yellow, orange, or red, drupaceous, subglobose, ellipsoid, or often dicoccous when fully developed or reniform with only 1 seed, fleshy, with calyx limb caducous or infrequently persistent; pyrenes 2-5, 1-celled with 1 seed in each cell, ellipsoid to reniform, bony or crustaceous; seeds medium-sized to large, ellipsoid, cylindrical, or plano-convex; testa membranous; endosperm fleshy; radicle ascending.
About 30 species: tropical and subtropical Africa and Asia; four species (one endemic) in China.
The circumscription and separation of genera of Vanguerieae and especially Canthium, Meyna, Psydrax, Pyrostria Commerson ex Jussieu, Vangueria Jussieu, and their closely related genera are problematic, controversial, and far from a full resolution. Lantz and Bremer (Bot. J. Linn. Soc. 146: 257-283. 2004) provided revised circumscriptions of several genera; in particular, they synonymized Meyna with Canthium and moved some species from Canthium to Psydrax. The Asian lineages have not yet been studied deeply, and the Chinese species may yet be reclassified.
The name Canthium cavaleriei H. Léveillé (Repert. Spec. Nov. Regni Veg. 10: 434. 1912) is based on a specimen from Guizhou; this name was not treated in FRPS. As the specimen has not been seen and its description is scanty, its identity is unknown. It has been suggested to be related to Lasianthus, but according to Lauener and Ferguson (Notes Roy. Bot. Gard. Edinburgh 32: 103. 1972) that is incorrect.
