1. Sagittaria Linnaeus, Sp. Pl. 2: 993. 1753.
慈姑属 ci gu shu
Lophiocarpus (Kunth) Miquel (1870), not Turczaninow (1843); Lophotocarpus T. Durand; Sagittaria sect. Lophiocarpus Kunth.
Herbs, aquatic, often stoloniferous and tuberiferous. Leaves aerial, floating, or submerged, linear, lanceolate, deeply cordate, or sagittate. Inflorescences usually of 3-flowered whorls each with 3 bracts. Flowers unisexual or polygamous, upper ones male, with longer and slender pedicels, lower ones female or bisexual, with shorter and thickened pedicel. Stamens (6-)9 to numerous. Carpels numerous, spirally arranged, each with 1 ovule; styles apical or subadaxial. Achenes laterally compressed, margins usually winged, with an apical or lateral stylar beak.
About 30 species: tropical and temperate regions; seven species (two endemic) in China.