1. Monochoria korsakowii Regel & Maack in Regel, Mém. Acad. Imp. Sci. Saint Pétersbourg, sér. 7. 4(4): 155. 1861.
雨久花 yu jiu hua
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.
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].
The entire plant is frequently used as feed for poultry and livestock.