Iris potaninii Maxim.

Rhizomes erect, short, tough. Roots thick. Leaves linear, 4--16 cm × 2--4 mm at anthesis, ca. 20 cm × 3--4 mm in fruit, base surrounded by dense, strongly curled fibers, apex rather abruptly contracted, subacute. Flowering stems not emerging above ground; spathes 2, narrowly lanceolate, 4--4.5 cm, membranous, 1-flowered. Flowers yellow, dark violet, or purplish blue, 3.5--5 cm in diam. Perianth tube 1.5--3.7 cm; outer segments strongly marked around yellow, dense beard, obovate, 3--4 × 1.2--1.5 cm, apex retuse; inner segments erect, oblanceolate, 2.5--3 cm × 8--10 mm, apex retuse. Stamens ca. 1.5 cm; anthers purple. Ovary ca. 7 mm. Style branches ca. 2.8 cm × 6 mm. Capsule broadly ellipsoid, 2.5--3 × 1.3--1.6 cm, apex shortly beaked; valves remaining united apically. Seeds pyriform, ca. 3 mm in diam., arillate. Fl. May--Jun, fr. Jul--Sep. 2 n = 22.

Gansu, Qinghai, Sichuan, Xizang [Mongolia, Russia].

Stony or dry hillsides; 3200--5000 m.