Monochoria vaginalis (N. L. Burman) C. Presl ex Kunth var. korsakowii (Regel & Maack) Solms.

Herbs aquatic, glabrous. Vegetative stems stout. Leaves radical or alternate and cauline. Radical leaves to 30 cm; leaf blade broadly cordate to ovate-cordate, 4--10 × 3--8 cm, densely veined, base cordate with basal lobes rounded, margin entire, apex acute to acuminate. Flowering stems erect, 30--70 cm, base sometimes purplish red. Inflorescences remaining erect after anthesis, racemose to paniculate, 10--20-flowered or more. Pedicels 5--10 mm. Perianth segments blue, elliptic, 1.2--2 cm, apex obtuse. Larger stamen: filament appendaged; anther 4--5.2 mm. Smaller stamens: filament filiform; anthers 2.5--3.5 mm. Capsule narrowly ovoid, 1--1.8 cm. Seeds 1.1--1.4 mm; wings 8--10. Fl. Jul--Aug, fr. Sep--Oct.

The entire plant is frequently used as feed for poultry and livestock.

Pools, rice fields, banks of lakes. Anhui, Hebei, Heilongjiang, Henan, Hubei, Jiangsu, Jilin, Liaoning, Nei Mongol, Shaanxi, Shandong, Shanxi [Indonesia, Japan, Korea, Pakistan, Russia (Siberia), Vietnam].