It is a rhizomatous herbaceous perennial, from Europe (including France, Italy, Switzerland, Austria, Czech Republic, Slovakia, Germany, Hungary, Poland, Romania, Bulgaria, Former Yugoslavia, Belarus, Estonia, Latvia, Lithuania, Moldova, Ukraine and northern Turkey) and Central Asia (including Armenia, Azerbaijan and Siberia).
It has long green grass-like leaves, tall stem, 2–5 violet-blue, to blue, and occasionally white flowers.
[9][12][13] The stems bear 2–5 (normally three) flowers, at the terminal ends between late spring and early summer, between May and June.
[6][8] It has 3 brown paper-like spathes (leaves of the flower bud), that are reddish at the base, measuring between 3–5 cm (1–2 in) long.
[8][29] It is known as iris de Sibérie (in French), sibirische Schwertlilie or Wiesen-Schwertlilie (in German) and strandiris (in Swedish).
[28][30] It was called Iris augustifolia media by the 16th century Flemish botanist Carolus Clusius.
[3] It was collected in Siberia by monks in the Middle Ages and grown in monasteries, later it was distributed around Europe, where there are now many cultivars.
[3] Within Europe,[17][15][35] it is found in west France,[4] Italy,[11][24][36] Switzerland,[4][6] Austria, Czech Republic and Slovakia,[27] Germany, Hungary,[27] Poland, Romania, Bulgaria,[4] Former Yugoslavia,[4] Belarus, Estonia, Latvia, Lithuania, Moldova, Ukraine[27] and northern Turkey.
Including Ontario (in Canada), Connecticut, Maine, Massachusetts, New York, Pennsylvania, Virginia and California.
[7][28] It is found growing in damp woodland,[27][38] wet meadows, grasslands or pastures,[16][27][38] reed swamps by lakes, and beside streams.
[4][35] They generally gain a lot of moisture from snow-melt of mountains, flooding streams and soaking areas beside them.
[7] According to IUCN Red List criteria, it is 'Vulnerable' (VU) (in the Czech Republic,[39] Hungary, Ukraine) and it has become 'Extinct' in the Wild (EW) in Slovakia.
[27] The UK national collection of Siberian irises is kept by Alun and Jill Whitehead at Aulden Farm, 3 miles (4.8 km) south of Leominster in Herefordshire.
[14] The iris should be grown in well-drained,[4][13] fertile,[10] neutral to slightly acidic soils (the pH level should be more than 5.6).
[16][38] If the soil has a high sand or clay content, large amounts of organic material (such as compost or well rotted manure) should be incorporated at planting time.
[13] The iris can also be used in mixed plantings with grasses and other perennials to create naturalised gardens and meadows.
[10] The National Collection (of Siberian Irises in UK) is held at Lingen Nursery, on the Welsh border.
[10] The plant position must be prepared before hand with plenty of compost (or manure) added to the soil to improve the fertility.
[22] The following cultivars have gained the Royal Horticultural Society's Award of Garden Merit (in the UK):- Like many other irises, most parts of the plant are poisonous (rhizome and leaves), if mistakenly ingested can cause stomach pains and vomiting.
[12] Johan Peter Falk noted that the Tara Tartars of Russia (West Siberia) coloured cloth yellow with Iris sibirica flowers and the Votyaks, Mordvins and Kalmyks derived red dye from Galium species.
[17] An old traditional usage before the wedding night, Polish girls eat the cooked fruit (seeds) of Iris sibirica to help improve contraception.