Iris dahurica Herbert ex Klatt.

Rhizomes creeping, branched, long. Roots thick. Leaves linear, 5--15 cm × 1.5--3 mm at anthesis, ca. 30 cm × 5 mm in fruit, midvein absent, base surrounded by brown fibers. Flowering stems short; spathes 2 or 3, narrowly lanceolate, 1- or 2-flowered, apex acuminate. Flowers yellow, 4--5 cm in diam. Perianth tube 2.5--3.5 cm; outer segments elliptic to ovate, with brown, linear patterns; inner segments erect, oblanceolate, 2.5--3 cm × ca. 4 mm. Stamens ca. 2 cm; anthers yellow. Ovary cylindric. Style branches bright yellow, ca. 2.5 cm. Capsule ellipsoid, 3.5--4.5 × 1--1.5 cm, apex acute. Fl. Apr--May, fr. Jun--Aug. 2 n = 22, 26*.

Iris flavissima is here treated as a distinct, E Asian species, but is often placed in synonymy under the widespread, Eurasian species I. humilis Georgi ( I. arenaria Waldstein & Kitabel).

Dry grasslands, fixed desert fields. W Heilongjiang, W Jilin, Nei Mongol, Ningxia, Xinjiang [Kazakhstan, Mongolia, Russia].