Iris ruthenica Ker Gawl.

I. ruthenica is close to I. uniflora Pall. ex Link growing in Siberia (Transbaykal area), the Far East (Amur River basin, Primorskiy region) and northeastern Mongolia. On steppe and stony slopes. I. uniflora differs in the shorter, thick, coriaceous, reddish leaves. Z 4. New.

Iris ruthenica is very variable and grades into I. uniflora. Iris ruthenica var. nana is said to have flowering stems only 5--5.5 cm, but, according to one of us (Noltie), the type of I. ruthenica is a similarly small plant, so var. nana cannot be maintained as distinct. Iris ruthenica var. brevituba, with a short perianth tube, is similarly not worth maintaining. White-flowered forms have been recognized as I. ruthenica f. leucantha Y. T. Zhao (Acta Phytotax. Sin. 18: 56. 1980).

Rhizomatous plant 20-30 cm. Leaves linear-lanceolate, somewhat arch-like, curved-decumbent, 40 cm x 0.4-0.6 cm. Flowers blue-violet, solitary on short peduncles (10-20 cm). V - mid spring to mid autumn, in St. Petersburg April-October. Fl -May-June for 2-3 weeks. Fr - August. P - by seed and division. For group planting and the rock garden. Does well in sunny places and in semishaded places. Z 4.

Rhizomes creeping, branched, 3--5 mm in diam. Roots fibrous. Leaves green or grayish green, linear, 7--25 cm × 1--3 mm, parallel veins 3--5, base surrounded by maroon-brown fibers, apex long acuminate. Flowering stems 2--20 cm, slender, 2- or 3-leaved; spathes 2, green, reddish purple at margin, lanceolate or broadly so, 2--3.5 cm × 8--10 mm, 1-flowered. Flowers violet, 3--5.5 cm in diam.; pedicel 6--10 mm. Perianth tube 0.5--1.5 cm; outer segments with white- and deep purple-mottled patterns, oblanceolate, ca. 4 cm × 8--10 mm; inner segments erect, narrowly oblanceolate, 3.2--3.5 cm × ca. 6 mm. Stamens ca. 2.5 cm; anthers milky white. Ovary ca. 1 cm. Style branches 3.5--4 cm. Capsule globose to ovoid, 1.2--1.5 cm, 6-veined, apex not beaked. Seeds globose or pyriform, with milky white aril. Fl. May--Jun, fr. Jul--Aug. 2 n = 84.

Siberia (southern regions), Central Asia (Tien Shan), northern Mongolia and northern China. Meadows, forest margins, grassy and stony slopes.

Anhui, Gansu, Guizhou, Hebei, Heilongjiang, Henan, Hubei, Hunan, Jiangxi, Jilin, Liaoning, Nei Mongol, Ningxia, Qinghai, Shaanxi, Shandong, Shanxi, Sichuan, Xinjiang, Yunnan [Kazakhstan, Korea, Mongolia, Russia; E Europe].

Pinus forests, grasslands, hillsides, sunny sandy places; 1800--3600 m.

Iris ruthenica var. brevituba Maximowicz; I. ruthenica var. nana Maximowicz.