溪荪 (原变种) xi sun (yuan bian zhong)

Iris extremorientalis Koidzumi; I. nertschinskia Loddiges; I. sibirica Linnaeus var. orientalis Baker; I. sibirica var. sanguinea (Donn ex Hornemann) Ker Gawler.

Inner surface of leaf sheaths without silver-white, metallic gloss. Flowers bluish violet or white, 6--7 cm in diam. Capsule broadly cylindric, long, 3.5--5 × 1.2--1.5 cm, glabrous. 2 n = 28*.

Damp meadows, sunny pond banks, hillsides; ca. 500 m. Heilongjiang, Jilin, Liaoning, Nei Mongol [Japan, Korea, Mongolia, Russia].

White-flowered forms, which occur in NE Heilongjiang and Japan, have been recognized as Iris sanguinea f. albiflora Makino (J. Jap. Bot. 6(11): 32. 1930).