Iris tigridia is a plant species in the genus Iris; it is also in the subgenus Iris and in the section Pseudoregelia. It is a rhizomatousperennial, from Kazakhstan, Russia, Mongolia and China. It has dark green or greyish green, grass-like leaves, a short slender stem and a single (or rarely 2) flowers that are either violet, dark blue, blue-purple, dark purple, mauve, lilac, lavender, or light purple. It is cultivated as an ornamental plant in temperate regions.
Description
It has small compact rhizomes.[3][4] Which are brown,[5] yellow or white, fibrous.[6] Underneath the rhizome are numerous fleshy, secondary roots,[3] which are between 3 and 4 mm wide.[6] On top of the rhizome are the dense, brown,[7][8][9] or dark brown,[10] fibrous remains of last seasons leaves.[11][12] It creates small tufted plants.[8][12]
It has dark green[6] or greyish green leaves[4][5][12] that can grow up to between 5 and 30 cm (2 and 12 in) long, and between 1.5 and 6 mm wide.[4][10][13] At the time of flowering, they are 5–13 cm (2–5 in) long,[3] and between 1.5 and 2 mm wide.[6] They then elongate to the final height of up to 30 cm tall.[5][6] They are grass-like, and they can be erect and linear[3][4] or slightly curved.[8][10] They do not have a midvein,[4][6] but have an acuminate apex (pointed) tip.[4][6][8] This form separates them from Iris potaninii.[11] In mild temperate areas, they are evergreen (lasting through the winter).[9]
It has a slender stem,[4][6] that can grow up to between 3 and 15 cm (1 and 6 in) tall.[14][15][16] Sometimes, the stem seems to only just appear above ground.[3][4][6]
The stem has 2[10] yellow-green (scarious) membranous spathes (leaves of the flower bud).[3][4]
They are lanceolate and between 3 and 4 cm (1 and 2 in) long,[8] with a pointed tip.[6]
The stems hold 1 (or rarely 2[13]) terminal (top of stem) flowers, blooming between April and May[7][11] (normally in May).[3][4][5]
Like other irises, it has 2 pairs of petals, 3 large sepals (outer petals), known as the 'falls' and 3 inner, smaller petals (or tepals), known as the 'standards'.[19] The falls are
obovate, and 3–4 cm (1–2 in) long,[3][4][8] and 1–1.5 cm wide.[3][4][6] In the centre of the petal, it has a white patch[13] and a beard,[7][9][10] with blue-white[3] or white hairs[17] tipped with yellow[2][5][13] or yellow hairs.[4][6]
The erect,[3] or tilting outwards,[6] standards are oblanceolate,[4][6] and 2.5–3 cm (1–1 in) long and 0.4–0.7 cm wide.[3][4][6] They are darker shade than the falls.[3]
After the iris has flowered, between June and July,[9] or up to August,[4][6] it produces an ovoid,[4][6] or fusiform (spindle shaped),[9][12] seed capsule. That is between 2.5 and 4 cm (1 and 2 in) long,[3][6][8] and between 1.5 and 2 cm in diameter.[6] It has a beak like top attached to the remains of the perianth tube.[3][4][6] Inside the capsule are roundish[3] or pear shaped (pyriform) seeds.[4][6]
They have a creamy[3] or yellowish white aril (appendage).[4][6]
In 2011, a chromosome and karyotype analysis study was carried out on the rhizomes of Iris tigridia. It found that the chromosome number of Iris tigridia was 2n=18.[21]
It is also commonly known as 'thick-root iris' in China.[22] or 'coarse roots iris'.[6]
In Russia, it is commonly known as 'tiger Iris'.[6][23][24]
It is known as 'Bartsooxor tsaxildag' in Mongolian.[25]
The Latin specific epithettigridia refers to 'tigris' or tiger-like. This refers to the colour marking of the perianth,[26][27] or the rather motley coloured flower of the iris.[10]
It was then published by Ledebour in 'Icones Plantarum novarum vel imperfecte cognitarum Floram rossicam' (Icon. Pl. Fl. Ross.) tab. 342. in 1830 (or 1833,[6]) with a colour illustration,[2] then by Karl Maximovich in the 'Bulletin of the Academy of Sciences St Petersburg' (Bull. Acad. Sci. St. Petersb.) Vol.26 on page530 in 1880 and by C.H. Wright in the 'Journal of the Linnean Society, Botany' (Journ. Linn. Soc. Bot.) Vol.36 on page 85 in 1903.
It was once placed with Iris potaninii and Iris pumila in the Pogoniris group,[11] before being re-classified as in the Pseudoregelia section.
It grows in (rocky or gravelly) screes,[7][9][36] on the dry hillsides (or slopes),[7][8][12] in dunes,[31] in sandy meadows or grasslands,[6][10][31] in steppes,[8][9][36] and beside forest margins.[4][5]
They can be found at an altitude of 0–2,000 m (0–6,562 ft) above sea level.[9][12]
Conservation
It is listed as 'rare' in Russia.[37]
It is also rare in Mongolia.[8]
It is found in Dauria and Sokhondinsky State Biosphere Reserve (in Chita).[23]
Cultivation
It is hardy to Zone H3 in Europe,[13] meaning that it is hardy to −10 to −15 °C (14 to 5 °F).[38] In non-hardy areas, it can be grown in an alpine house or bulb frame[15] due to the fact that the plant needs to be protected from winter moisture.[9]
It has been tested for hardiness in Russia, in the botanical gardens of Barnaul (the South-Siberian Botanical Garden), Novosibirsk (Central Siberian Botanical Garden), Chita (Trans-Baikal Botanical Garden) and Saint Petersburg Botanical Garden. Only in St. Petersburg, it was found to be not hardy.[9]
It can be grown in well-drained soils, in a sunny position.[9][15]
It is thought best planted between August and September.[11]
Propagation
It can be propagated by division or by seed growing. It can only be divided, when the plant makes new side-shoots.[7]
Hybrids and cultivars
Several cultivars have been introduced including;
'Violet Peafowl' (purple)
'Starry Diamond' (violet blue)
'Rainbow in May' (purple-pink)
'Bright Vitas' (blue).
All four cultivars are between 12 cm and 14 cm tall, flower between April and May, are hardy, drought tolerant and salt tolerant.[39][40]
'Medianite' (a lilac and pink form, but lost in cultivation)[2]
Iris tigridia var. fortis (Y. T. Zhao) is listed as a variant from (Jilin, Inner Mongolia and Shanxi) in China. It grows 10–20 cm (4–8 in) tall, with violet flowers.[14][16]
Toxicity
Like many other irises, most parts of the plant are poisonous (rhizome and leaves), if mistakenly ingested can cause stomach pains and vomiting. Also handling the plant may cause a skin irritation or an allergic reaction.[41]
Uses
It is used in gardens, also in herbal medicines,[8] and as a fodder plant for farm animals.[8][25]
It has been eaten by cattle and horses, at most times of the year. It is also consumed by goats but it is thought to be an undesirable food source.[25]
^Smith, A.W.; Stearn, William T. (1972). A Gardener's Dictionary of Plant Names (Revised ed.). Cassell and Company (published 1963). p. 314. ISBN0304937215.