Rhizomes creeping, thick. Leaves grayish green on both surfaces, linear, 15--45 cm × 3--10 mm, midvein absent, base reddish. Flowering stems 10--40(--70) cm × 4--6 mm, hollow, 2- or 3-leaved; spathes 2 or 3, green, slightly reddish brown at margin, 5.5--12 × 0.8--1.2 cm, (1 or)2-flowered. Flowers pale lilac or bluish violet to dark violet, rarely white, 6.5--7.5 cm in diam.; pedicel 2--6 cm. Perianth tube 1--1.2 cm; outer segments obovate, with darker lines and markings on central, whitish or yellowish patch, 4.5--5 × ca. 2.5 cm; inner segments ± erect, light violet, lanceolate, ca. 4 × 1.5 cm. Stamens ca. 2.5 cm; anthers milky white. Ovary ca. 2 cm. Style branches ca. 3.5 cm. Capsule cylindric, 4--5.5 × 1.5--1.8 cm, 3-angled, distinctly 6-veined, apex not beaked, obtuse. Seeds brown, semiorbicular, flat. Fl. Jun--Jul, fr. Aug--Oct. 2 n = 40.
Damp hillsides, meadows, streamsides; 2300--4300 m. Sichuan, Xizang, Yunnan [Myanmar].
White-flowered forms, which are restricted to Yunnan, have been recognized as Iris bulleyana f. alba Y. T. Zhao (Acta Phytotax. Sin. 18: 54. 1980).
