1. Alisma plantago-aquatica Linnaeus, Sp. Pl. 1: 342. 1753.
泽泻 ze xie
Tubers 1-3.5 cm in diam. Aerial leaves with petiole 1.5-30 cm; leaf blade broadly lanceolate or elliptic to ovate, 2-11 × 1.3-7 cm, sometimes larger, veins 5, base subcordate or truncate but sometimes cuneate, apex usually acuminate. Panicles 15-50 cm, in 3-8 whorls of 3-9 branches. Pedicel 1-3.5 cm. Sepals broadly ovate, 2.5-3.5 × 2-3 mm. Petals white or purplish white, suborbicular, larger than sepals, margin denticulate. Anthers elliptic, ca. 1 mm. Carpels regularly arranged; styles erect, filiform, longer than ovary, 0.7-1.5 mm, stigmatose in upper 1/9-1/5 of their length. Achenes elliptic or suboblong, ca. 2.5 × 1.5 mm, 1- or 2-grooved abaxially; lateral pericarp thickish, opaque. Fl. and fr. May-Oct. 2n = 14*.
Margins of lakes, ponds, marshes, channels, slow-moving rivers. Heilongjiang, Jilin, Liaoning, Nei Mongol, Shaanxi, Xinjiang, Yunnan [Afghanistan, India, Japan, Kazakhstan, Korea, Kyrgyzstan, Mongolia, Myanmar, Nepal, Pakistan, Russia, Tajikistan, Thailand, Uzbekistan, Vietnam; Africa, SW Asia, Australia, Europe, North America].