Rotala cordata Koehne

Herbs, annual, terrestrial or amphibious, 8-30 cm. Stem branched, 4-winged; wings white, broad, extending into margins of leaves and bracts. Leaves decussate, narrowly oblong to lanceolate, 8-25 × 3-8 mm, base broad, cordate, clasping, apex obtuse. Bracts lanceolate to oblong, smaller on lateral inflorescences, 4-6 mm × 1.5-2 mm. Flowers solitary, subsessile, in bracts of axillary spikes; bracteoles minute, at base of floral tube, scarious. Floral tube 4-merous, broadly campanulate, 1-2 mm; sepals 4, pink-tinged, deltate, ca. 1/3 as long as floral tube, acuminate; epicalyx absent. Petals 4, obovate. Stamens 4, anthers reaching margin of floral tube. Ovary globose; style exserted. Capsules globose, ca. 1.5 mm in diam., 3-valved. Seeds ca. 0.5 mm. Fl. Nov.

Wet places by water. Guangxi, Hainan [NE India (Darjeeling), Laos, Thailand, Vietnam].

Rotala diversifolia Koehne.