Description from
Flora of China
Iris flavissima Pallas var. bloudowii (Ledebour) Baker; I. flavissima var. umbrosa Bunge.
Rhizomes not widely creeping, thick. Roots thick. Leaves grayish green, sword-shaped, slightly curved, 8--12 cm × 4--8 mm at anthesis, 15--25 × 0.8--1.2 cm in fruit, midvein absent, veins 5 or 6, apex shortly acuminate. Flowering stems 8--10(--30) cm, base with erect, slender, sheathlike leaves persisting as fibers; spathes 2 or 3, with some reddish color, oblong-lanceolate, ca. 4 × 1.6--2 cm, 2-flowered, apex obtuse. Flowers bright yellow, 5--5.5 cm in diam.; pedicel 6--10 mm. Perianth tube 1--1.5 cm; outer segments obovate, ca. 4 × 2 cm, beard yellow; inner segments erect, oblanceolate, 3--4.5 × 1--1.2 cm. Stamens 1.8--2.2 cm. Ovary ca. 1.5 cm. Style branches bright yellow, ca. 2.5 cm. Capsule narrowly ovoid, apex acute, obscurely beaked. Seeds dark brown, ellipsoid, ca. 5 × 3 mm, with white aril. Fl. May, fr. Jun--Aug.
Grasslands at forest margins, sunny dunes. Xinjiang [Kazakhstan, Mongolia, Russia].