Rhizomes long, slender, stoloniferous. Leaves glaucous, 11--25 × 0.8--1.1 cm, elongating to 35 cm after anthesis, 10--12-ribbed. Flowering stems 9--13 cm; spathes 2, lanceolate, 3.3--6.2 × 0.1--0.4 cm, 2-flowered. Flowers white, 3--4 cm in diam.; pedicel long. Perianth tube short, 1--5 mm; limb of outer segments spreading, with central, yellow signal patch spreading into claw, obovate, 1.8--2.4 × 1--1.6 cm, apex rounded; inner segments white, obovate, 1.4--1.9 cm × 6--9 mm. Stamens 1--1.4 cm. Style branches white, linear, 1.5--2 cm × 3--4 mm. Capsule ovoid, 2.3--2.7 × 1.2--1.5 cm, strongly 3-angled, apex shortly beaked; fruiting pedicel long. Fl. Apr--May, fr. Jun--Jul.

Forest margins, meadows, damp hillsides along ditches; ca. 1500 m. Jilin [Korea].