Iris subg. Iris

Subgenus Iris is one subgenus of Iris.

Iris as a plant was originally named by Carl Linnaeus in his book Systema Naturae (in 1735), with a great number of species being added into the genus. Including new ones that were found after the book's publication. The division of irises into various subgroups, has taken various forms over the years. By the 19th century botanists had created new genera such as Evansia, Hermodactylus, Moraea, Oncocyclus, and Xiphion. Opinion was often divided whether to split the genus into several parts or lump them back into Iris. From J. G. Baker, who separated some such as Moraea and Xiphion from Iris in his book 'Handbook of the Irideae' (published in London) in 1892. Then William R. Dykes, who clarified the situation by a compromise in his monograph The Genus Iris (by Cambridge University Press, 1913; later reprinted in 1974 by Dover). He was the first to term the subgroup as Iris sect. Iris. G. Rodionenko's 1961 reclassification in The Genus Iris (written in Russian, Moscow, 1961) was more comprehensive in that he split the genus into five genera: Iris (which included all rhizomatous irises).^[1] A taxonomic revision by Brian Mathew in 1981 (The iris, New York: Universe Books), recognized six subgenera: Nepalensis Dykes, Xiphium (Miller) Spach, Scorpiris Spach, Hermodactyloides Spach, Iris L. and Limniris Tausch.^[2] Recently, DNA analysis has been used to determine groupings.^[3]

The subgenus Iris subg. Iris is an autonym.^[4] It has been divided into six sections:^[5]

Sections Oncocyclus and Regelia are also called aril irises.

This is the largest section of the subgenus, the true bearded irises. Most irises come from Southern or eastern Europe.^[2] 'Pogon' refers to the Greek word for beard.^[6] It has several species of iris including;

It also includes thousands of ornamental plant cultivars, which have been divided into various height categories.^[7]

• MDB – Miniature dwarf bearded
• SDB – Standard dwarf bearded
• IB – Intermediate bearded
• BB – Border bearded
• MTB – Miniature tall bearded
• TB – Tall bearded

This section of irises was first described by Spach. Most of the Irises come from Russia and Northwest China. Mostly rhizomatous, and flowering in late spring.^[2] 'Psammiris' is derived from the Greek word psammos for sand.^[6] The type species for this section is Iris arenaria

It includes;

Oncocyclus irises are rhizomatous perennials. They also generally need rich soils that drain easy and are in full sun. Most also prefer a dry period after flowering.^[9] The Oncocyclus irises are mostly from Turkey, Caucasus and Iran. The plants usually have only one flower,^[2] which is veined or spotted.^[10] Some of these species have been bred with bearded irises to create unique colours and markings.^[2] Oncocyclus is a Greek word, with onco meaning mass, or bulk, and cyclus meaning circle.^[11] In 1846, the term 'Oncocyclus' was first used by C.H. Siemssen as the Genus Oncocyclus in 1846 in Botanische Zeitung. Baker then re-classified it to a subgenus in 1877, than Dykes lowered it to a section in 1914, where it currently remains.^[12]

Mostly from the mountainous regions of Iran, Afghanistan and the Altai Mountains.^[13] Most irises have a stem that has 2 flowers.^[2] It was named in 1904 by Robert Lynch in his book The Book of The Iris after Dr Regel.^[14] The type species for this section is Iris korolkowii

Hybrids of Regelia irises and Oncocyclus irises are known as Regelicyclous.^[15]

Mostly from the desert area of Central Asia, Iran and Afghanistan. The type species for this section is Iris falcifolia Most irises have beards on the falls and standards.^[2] Etymologically, hexa refers to the number 6 and pogon refers to the Greek word for beard.^[6]

Mostly from the mountainous regions of Eastern Asia. Most irises have flowers that have blotches or colour spots on.^[2] The type species for this section is Iris tigridia