1. Hydrocharis dubia (Blume) Backer, Handb. Fl. Java. 1: 64. 1925.
水鳖 shui bie
Pontederia dubia Blume, Enum. Pl. Javae 1: 33. 1827; Hydrocharis asiatica Miquel; H. morsus-ranae Linnaeus; H. morsus-ranae var. asiatica (Miquel) Makino; Limnobium dubium (Blume) Shaffer-Fehre; Monochoria dubia (Blume) Miquel.
Leaves floating or sometimes emerged; blade cordate or orbicular, 4.5-5 × 5-5.5 cm, 5-7-veined, base cordate, apex rounded. Male flowers 5 or 6 in spathe; peduncles 0.5-3.5 cm; pedicels 5-6.5 cm; sepals ca. 6 × 3 mm; petals yellow, ca. 1.3 × 1.7 cm; stamens 12, inner 3 stamens staminodal; anthers 1-1.5 mm; staminodes hairy at base and papillose at apex. Female flowers larger than male flowers; sepals ca. 1.1 cm × 4 mm; petals white, yellow at base, ca. 1.5 × 1.8 cm; staminodes 6; glands 3, reniform; styles ca. 4 mm, with dense glandular hairs. Fruit berrylike, spherical to obovoid, 8-10 mm, ca. 7 mm in diam. Seeds gradually acute toward apex. Fl. and fr. Aug-Oct. 2n = 16.
Still water. Anhui, Fujian, Guangdong, Guangxi, NE Hainan, Hebei, Heilongjiang, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Jilin, Liaoning, Shaanxi, Shandong, Sichuan, Taiwan, Yunnan, Zhejiang [Bangladesh, India, Indonesia, Japan (including Ryukyu Islands), Korea, Myanmar, New Guinea, Philippines, Thailand, Vietnam; N Australia].