Iris ruthenica

From Kazakhstan Encyclopedia

Template:Italic titleTemplate:Taxobox Iris ruthenica, sometimes called 'Ever Blooming Iris' (in the UK), 'Russian Iris', 'Pilgrim Iris' and 'Hungarian Iris' (in Europe), is a species in the genus Iris- subgenus Limniris. It is a rhizomatous perennial, with a wide distribution, ranging from eastern Europe to Central Asia. It has grass-like leaves, thick stem and violet or bluish lavender flowers which are marked with violet veining.


Iris ruthenica is very variable and hybrids can look very similar to Iris uniflora.[1] The other species in the Iris series Ruthenicae. It can be variable with its leaf length and width, and flower height.[2]

It has a creeping rhizome,[3][4][5][6] (about 3-5mm in diameter) which is branched and has fibrous roots.[1] The creeping rhizome forms a clump or a grass-like tuft plant.[2][3][7]

It has bright green leaves[3][6][7][8][9] or greyish green leaves.[1][5] That are tall and thin, and grass-like,[2][9][10][11] measuring between 10 – 40 cm (8–13 in) long and 2 – 6 mm wide.[1][2][3][4] The leaves can grow longer than the flower stem.[9]

The plant (stem and flowers) grows to a height of between 3–20 cm [4] ref name=signa/>[1][2][6][10](12 in).[7]

The thick stem is 2–3 cm wide,[9] can grow to heights of between 3–20 cm.[1][3][4][10] It has the remains of last years leaves at the base of the stem.[9]

It blooms in spring,[8] (between May, June and July in the UK)[7][12] or early to mid summer,[2] with one normally, but occasionally 2 fragrant flowers.[1][2][3][4][6][7][8][9][11][12]

The large flowers are between 3–5 cm in diameter,[1][2][3][6] with a cylindric,[9] perianth tube measuring 0.5--1.5 cm long.[1][6] The flowers come in a range of blue shades between violet [1][2][7][12] and bluish lavender.[2][4][11] Which are marked with violet veining.[2][5][7][8] The falls (measuring 4.5–5 cm) are white.[2][3][5][6][7][11] The standards are (measuring 4–6 cm) are almost erect.[1][3][6] The bracts (measuring 3–5 cm ) are greenish with pink margins,[6] violet blue stigma,[8] and milky white anthers.[1]

It has a globose (globe-like) to ovoid shaped seed capsule (measuring 1.2--1.5 cm) in June–August (after the flowering period is over).[1][9][13] Once they are ripe, the seed capsules fully open and all the seeds are dispersed in one movement. Unlike other iris species.[13] The seeds are pyriform (pear-shaped) and have an aril (white appendage on the edge of the seed).[1][3] The aril disappears soon after and shrivels up.[13]


As most irises are diploid, having two sets of chromosomes. Which can be used to identify hybrids and classification of groupings.[14] It has a chromosome count: 2n=84 [1][12][15] (found by Simonet in 1934).[16]


It is written as 紫苞鸢尾 in Chinese script,[17] and known as 'zi bao yuan wei'.[1]

It is named after the region of the 'Ruthenia', in Transylvania and Romania,[13]

It has several common names; 'Ever Blooming Iris' (in the UK),[18][19] 'Russian Iris',[3][8][19][20] 'Pilgrim Iris' (sometimes called a synonym of Iris ruthenica),[16][21] and 'Hungarian Iris' in Europe.[10]

It is known as ungersk iris in Sweden.[22]

Iris ruthenica was first published by John Bellenden Ker Gawler in Botanical Magazine in 1808.[22][23] It was later published in 1811, as 'Iris ruthenica' with the common name 'Pigmy Iris' in Curtis's Botanical Magazine, vol. 34, table 1393.[16] Pigmy Iris is now used as the common name of Iris pumila.

It was mentioned the journals of Captain Beechy's Voyage (in 1825).[24]

It is mentioned in Cherepanov's Vascular Plants of Russia.[25]

It was verified by United States Department of Agriculture and the Agricultural Research Service on 42 October 2014.[22]

Iris ruthenica is an accepted name by the RHS.[19]

Distribution and habitat

Iris ruthenica is native to a wide region, including temperate Asia and Europe.[22]


It is found in southern Russia and Siberia,[4][8][9] through Central Asia,[26] (including Altai Mountains and Turkestan,[13] on the Tien Shen mountain range,[4] Kazakhstan and Mongolia)[27] to China and Korea.[1][2][6][10][12][28] Within Europe, it is found in Romania.[22]

It is listed with Iris bloudowii, Iris humilis, Iris lactea, Iris sibirica, Iris tenuifolia and Iris tigridia as being found in the Altai-Sayan region (where Russia, China, Mongolia and Kazakhstan come together).[29]


It is found on dry meadows (including grass plains and steppes), pine and birch forest edges and edges of woodland.[2][4][7] It can also be found in forest clearings in the forest-meadow mountain belt. Forming a thicket ground-cover.[4]

In Mongolia it is found under Pinus sylvestris/Betula platyphylla subtaiga forests, in montane meadow steppes with Festuca lenensis and Artemisia sericea and in Pinus sibirica/Picea obovata dark taiga forests (within the upper montane belt with Rubus saxatilis and Lathyrus humilis).[30]

Elsewhere in Eurasia, it is found in the Larch forests of Altai and Sayan mountains including Tuva).[31]

It is also found in Tuvan Forests as a subcanopy woody species.[32]

On the Altai Mountains, it is found with other mountain flowers including Siberian Dogs-tooth Violet (Erythronium krylovii), Altai Foxtail Lily (Eremurus), a variety of saxifrages, Aquilegia, Gentiana grandiflora, Papaver nudicaule and the yellow Iris bloudowii.[27]

At altitudes of between 1800 and 3600m.[1][2]


It is hardy to USDA Zone 2[3] or Zone 3.[5]

Iris ruthenica does not flower very well in the UK.[11] It is best cultivated in fertile soils that do not dry out.[8][13] It is best suited for Rock Gardens or at the front of a flower border.[8][10][11][14] Although sinks or troughs could be used.[11] It also grows well on dry peat banks[28] It is tolerant of semi-shade, but prefers full sun.[3][5][11]

Unlike many other irises, it can only be moved with success, during the spring and summer when it is in full growth.[10][11][13]

Iris ruthenica is grown in several Russian botanical gardens including, Barnaul, Ivanovo, Irkutsk, Kirov, Moscow, Rostov-on-Don, St. Petersburg, Stavropol, Tomsk, Omsk, Novosibirsk and Chita.[4]


It can be propagated by division or by seed.[5][13] The seeds should be sown in the autumn and the rhizomes divided in early spring.[4] The seeds germinate fairly quickly and new plants are easily raised.[13] But the young plants must not dry out.[10] The old and damaged rhizomes should be removed before replanting.[5]

Hybrids and Cultivars

Iris ruthenica var. nana was once thought to be a smaller variety of Iris ruthenica.[16][33] but this is now considered a synonym.[34]

Although, Iris ruthenica var. brevituba which has a small perianth tube[1] and violet flowers,[35] it is also now considered a variant.[36]

Iris ruthenica has the following known cultivars;



Other sources

  • Aldén, B., S. Ryman & M. Hjertson. 2009. Våra kulturväxters namn - ursprung och användning. Formas, Stockholm (Handbook on Swedish cultivated and utility plants, their names and origin).
  • Czerepanov, S. K. 1995. Vascular plants of Russia and adjacent states (the former USSR).
  • Khassanov, F. O. & N. Rakhimova. 2012. Taxonomic revision of the genus Iris L. (Iridaceae Juss.) for the flora of Central Asia. Stapfia 97:175.
  • Komarov, V. L. et al., eds. 1934–1964. Flora SSSR.
  • Mathew, B. 1981. The Iris. 83.
  • Tutin, T. G. et al., eds. 1964–1980. Flora europaea.
  • Waddick, J. W. & Zhao Yu-tang. 1992. Iris of China.

External links

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