The plant has tall branching stems, mid green leaves and violet, purple-blue, violet-blue, blue, to lavender flowers.
[4][5][6] The rhizomes are grey-brown, thick, and are covered with old (maroon-brown) fibrous leaf remains (of last seasons leaves).
[7][8][9] It has branched stems, which are very variable in height,[10] ranging from 10 cm (5 inches) up to 1 m (3 ft) tall.
[7][8] Iris setosa has mid-green leaves,[3][5][6] which are grass-like,[12] and lanceolate (sword-shaped).
[19] The sepals can be deeply veined dark purple with a yellow-white signal (centre).
[8] The plant is self-fertile,[16] being hermaphrodite (have both male and female organs) and it is pollinated by insects.
[7] The pale brown seeds[7][8] (about 2–3 mm in size[8]) have a distinct raised raphe (tissue ridge) the length of one edge.
[10][33][34] The name 'setosa' is derived from the Latin word 'seta' meaning 'bristle' (or hairy),[6] this refers to the standards being almost absent.
[37] It was first published by Link (based on an earlier description by Pallas) in 'Jahrbücher der Gewächskunde' (translated as 'Yearbook of Greenhouse').
[8][9] It was then published in William Rickatson Dykes (Iris 1913 p. 92) as 'Iris Brachycuspis', which later regarded as a synonym.
[4] In Canada, it is found along the shores of the Gulf of St. Lawrence and as far north as the estuary of Saint-Vallier, in Bellechasse county.
[14] The species is found in large amounts in Akkeshi, in eastern Hokkaido, Japan.
[2][6][18][16] They can also tolerate bog conditions,[17][29] especially during the growing season it needs a lot of moisture.
[2][3][29] It prefers to grow in partial shade, as full sun risks drought conditions.
[44] Iris setosa is one of the hardiest species of irises,[11] but does needs a cold dormant period in winter, and so does not do as well in warm climates.
[17] As a native plant of Alaska, it is extremely cold-hardy (minus thirty degrees F. wouldn't kill it).
[14] Division is best taken place in spring and autumn if possible, ideally in September[11] (about 4–6 weeks after flowering).
[15] It is approximately 80 cm (31 in) high, robust, low branching, with large purple flowers.
It has broader leaves then Iris setosa and has large flowers (similar to 'Iris laevigata') but has small bracts.
It was found in the Shiga Highlands in near the city of Nagano, in central Honshu in 1930 by Yokouchi and Koidzumi, and it was named after the area in where it was discovered.
These three hybrids of I. setosa are found only in limited areas of Honshu Island.
[15] Iris setosa also form hybrids with larger blue flag.
[4] Named cultivars include; Herbalists have used the rhizome of Iris setosa for centuries as an ingredient in various medicines, (similar to the usage of Orris roots).
[14] Although the plant is poisonous, its starchy roots can be made safe for human consumption via cooking.
[52] The Aleut also made a drink from the roots, to be used as a laxative,[53] but the Iñupiat considered the whole plant poisonous.
[12] Some Inuit tribes in Alaska also roasted and ground the seeds of the iris to be used as a coffee substitute.
[51][54][55] The flower petals can be used to create a violet-blue dye, when it is used with a chrome mordant (or fixing agent).