It is a rhizomatous herbaceous perennial, from Asia, including north east India, Nepal, Tibet, Bhutan, Burma and in China.

[5][6][7] The rhizomes are slender and cylindric in form and sometimes clothed with the fibrous remains of the leaves from last season.

The falls are larger, drooping, pendant shaped (in botany terms – obovate) and have a large white/yellow signal patch with violet or dark blue veining.

[3][7][11] The standards are smaller, narrower (oblanceolate), plain coloured, upright, and usually horizontal.

[8][9] It is written as 西藏鸢尾 in Chinese script and known as 'xi zang yuan wei' in China.

The Latin specific epithet clarkei refers to Charles Baron Clarke who had collected herbarium specimens (of the iris) in 1875.

[17][18] Unfortunately Baker had made a mistake, when he first described the iris, he had based his description of the plant, using a sketch drawn by Joseph Dalton Hooker (within Royal Botanic Gardens, Kew Herbarium).

[3] Hooker had found the plants in Tonglo in India and at Yakla in Sikkim (at an altitude of 10,000 ft above sea level).

Later, in 1907 more plants and seeds from Tonglo, arrived in the UK and the mistake was found [3] In 1910, in Curtis's Botanical Magazine, Tab.

Vol.136 published by Otto Stapf, he noted that plants raised in gardens did not match the description and that it should be classified as coming from a region similar to Iris delavayi in China.

[14] This plant has gained the Royal Horticultural Society's Award of Garden Merit, as well as being an accepted name.

[14] Iris clarkei comes from a wide range of north east Asia; including north east India, (Sikkim, Manipur, Darjeeling and the Chumbi valley) Nepal (Himalayas), Tibet (also known as Xizang in China), Bhutan, Burma (formerly known as Myanmar),[20] and in China (within the provinces of Xizang and Yunnan).

[5][14][7] It grows on damp, grassy hillsides and marshes, beside streams and lakes and also at the edge of rhododendron and Abies pine forests.

It is rare in cultivation in the UK, and is sometimes confused with dwarf forms of Iris setosa.

They will tolerate temperatures of up to – 15 degrees C.[7] But may survive lower if protected or well mulched in winter.

[9] They prefer soils with a ph level of 5.5 to 7 (acidic to neutral) and more moisture tolerant.