钝叶眼子菜 dun ye yan zi cai

Plants annual, submerged in fresh water. Rhizome absent, filiform. Stems ca. 0.8 mm in diam., slightly compressed and creeping at base, richly branched; a pair of nodal glands conspicuously present; turions terminal on axillary branches. Stipules axillary, free, 1-1.8 cm × 1.1-3.5 mm, convolute, membranous to herbaceous, often fibrous-persistent; leaves sessile, linear, 3-6 cm × 2.1-3.5 mm, 3(-5)-veined, lateral veins faint but visible, with narrow to broad rows of lacunae bordering obvious midvein, base narrowly cuneate, apex obtuse to rounded, indistinctly mucronate. Spikes in 2 or 3 whorls of opposite flowers, contiguous, broadly cylindric; peduncles 0.4-1.2 × length of fruiting spike. Carpels (3 or)4(or 5). Fruit obliquely obovoid, 2.6-3.6 mm, with a sharp abaxial keel distinct or indistinct. Fl. and fr. Jun-Oct. 2n = 26.

Ponds, lakes, rivers, streams. Heilongjiang [Japan, Kazakhstan, Kyrgyzstan, Mongolia, Myanmar, Russia; Europe, North America].