31. Guettarda Linnaeus, Sp. Pl. 2: 991. 1753.
海岸桐属 hai an tong shu
Authors: Tao Chen & Charlotte M. Taylor
Shrubs or trees, sometimes polygamo-dioecious, unarmed. Raphides absent. Leaves opposite or rarely ternate, decussate, usually with domatia; tertiary and/or quaternary venation often arranged in regular, often small rectangles or squares; stipules caducous, interpetiolar, generally triangular. Inflorescences axillary, cymose with axes often markedly dichotomous or scorpioid, several to many flowered, pedunculate with peduncle usually elongated [to sessile], bracts reduced [to well developed]. Flowers sessile to shortly pedicellate, unisexual or bisexual and monomorphic or at least sometimes distylous, sweetly fragrant. Calyx limb tubular or subcampanulate, truncate or irregularly denticulate. Corolla white or pink, salverform with tube infrequently curved, glabrous to variously pubescent inside; lobes 4-9, obtuse, imbricate (and quincuncial) in bud. Stamens 4-9, inserted in corolla tube, included; filaments short or reduced; anthers dorsifixed. Ovary 4-9-celled, ovules 1 in each cell, pendulous from apical placentas, anatropous, with funicle thickened; stigma capitate, included. Fruit red, purple, black, or rarely green, drupaceous, thinly fleshy, oblate (i.e., depressed globose), ellipsoid, or subglobose, with calyx limb persistent; pyrene 1, 4-9-celled with 1 seed in each cell, oblate, ellipsoid, or subglobose, often 4-9-angled or -grooved, with preformed germination pore at apex of each cell; seeds medium-sized, ellipsoid, straight or curved; testa membranous; endosperm absent or scanty; embryo cylindrical or compressed; cotyledons small; radicle ascending.
About 60-80 species: tropical forests, most in tropical America and Pacific region, one species widespread on coasts of Indian Ocean and E Pacific Ocean; one species in China.