4 Taxonomic issues

Up to 300 species have been placed in the genus Iris. Modern classifications, starting with W. R. Dykes' 1913 book, have subdivided them. Dykes referred to the major subgroupings as sections, but later authors have generally called them subgenera, while essentially retaining his groupings. Like some older sources, the influential classification by G. I. Rodionenko removed some groups (particularly the bulbous irises) to separate genera, but even if this is done the genus remains large and several subgenera, sections and/or subsections are recognised within it.

The major subgenera widely recognised are:

• Iris: bearded irises, growing from rhizomes.
• Limniris: beardless irises, growing from rhizomes.
• Xiphium, sometimes treated as genus Xiphion, the main group of bulbous irises.
• Nepalensis, sometimes treated as genus Junopsis; also bulbous.
• Scorpiris, sometimes treated as genus Juno; also bulbous.
• Hermodactyloides, sometimes treated as genus Iridodictyum, including the small Iris reticulata and some other similar species; also bulbous.

All modern authors regard the Snake's Head Iris as lying outside genus Iris, and classify it as Hermodactylus tuberosus.

Among the lower level subgroupings usually recognised is Oncocyclus, a section or subsection within subgenus Iris, containing the cushion irises or Royal irises. These constitute a magnificent group of plants remarkable for their large, showy and beautifully marked flowers. Between 30 and 60 species are classified in this section, depending on the authority. Compared with other irises the cushion varieties are scantily furnished with narrow sickle shaped leaves and the blossoms are usually borne singly on the stalks. The best-known kinds are atrofusca, barnumae, bismarckiana, gatesi, heylandiana, iberica, haynei, mariae, meda, paradoxa, sari, sofarana and susiana; the last-named being popularly called the "mourning iris" owing to the dark silver appearance of its huge flowers.

A closely allied group to the cushion irises are those known as Regelia, also within subgenus Iris, of which korolkowli, leichtlinii and vega are the best known. Some magnificent hybrids have been raised between these two groups, and a hardier and more easily grown race of garden irises has been produced under the name of regelio-cyclus. They are best planted in September or October in warm sunny positions, the rhizomes being lifted the following July after the leaves have withered.

5 Examples of Iris species

• Iris pseudacorus, the Yellow Flag or Yellow Iris, is common in Britain on river-banks, and in marshes and ditches. It is called the "water-flag" or "bastard floure de-luce" by John Gerard, who remarks that "although it be a water plant of nature, yet being planted in gardens it prospereth well." Its flowers appear in June and July, and are of a golden-yellow colour. The leaves are from 2 to 4 ft. long, and half an inch to an inch broad. Towards the latter part of the year they are eaten by cattle. The seeds are numerous and pale-brown; they have been recommended when roasted as a substitute for coffeeThis article discusses the coffee plant; for information on the beverage see coffee (drink). Coffea arabica Arabian Coffee Coffea benghalensis Bengal Coffee Coffea canephora Robusta Coffee Coffea congensis Congo Coffee Coffea liberica Liberian Coffee Coff, of which, however, they have not the properties. The astringent rhizome has diureticA diuretic is any drug that tends to increase the flow of urine from the body ( diuresis). Some common diuretics are caffeine and alcohol. Medically, diuretics are used to treat heart failure, cirrhosis of the liver, Hypertension and certain kidney diseas, purgative and emetic properties, and may, it is said, be used for dyeing black, and in the place of galls for ink-making.
• Iris foetidissima, the fetid iris, gladdon or roastbeef plant, the Xyris or stinking gladdon of Gerard, is a native of EnglandEngland is the largest, the most populous, and the most densely populated of the four " Home Nations" which make up the United Kingdom of Great Britain and Northern Ireland (UK). Occupying the south-eastern portion of the island of Great Britain, England south of DurhamFor other places called Durham, see Durham (disambiguation). Durham is a small city in County Durham in the north east of England, situated 25 km (15 miles) to the south of Newcastle upon Tyne. The River Wear flows through the city, enclosing the centre o and also of IrelandThe island of Ireland ire in Irish, Airlann in Ulster Scots) is the third-largest island in Europe. It lies on the west side of the Irish Sea, close to the island of Great Britain. It is composed of the Republic of Ireland in the south and Northern Irelan, southern EuropeFor the band of the same name, see Europe (band . Europe is a continent forming the westermost part of the Eurasian supercontinent. Europe is bounded to the north by the Arctic Ocean, to the west by the Atlantic Ocean, to the south by the Mediterranean Se and North AfricaNorth Africa is the region of the continent of Africa north of the Sahara desert, comprising the Maghreb, including Libya and Egypt, and also by some definitions the Sudan. North Africa is vastly more uniform ethnically than anywhere in Africa south of th. Its flowers are usually of a dull, leaden-blue colour; the capsules, which remain attached to the plant throughout the winter, are 2 to 3 in. long; and the seeds scarlet. When bruised this species emits a peculiar and disagreeable odour.
• Iris germanica of central Europe, "the most common purple Fleur de Luce" of Ray, is the large common blue iris of gardens, the bearded iris or fleur de luce and probably the Illyrian iris of the ancients.
• Iris florentina (often misspelled Iris fiorentina), with white or pale-blue flowers, is a native of the south of Europe. Modern authorities treat it as a subspecies, Iris germanica florentina, of I. germanica. It is the source of the violet-scented orris root used in perfumery. From the flowers of Iris florentina a pigment, the "verdelis," "vert d'iris," or iris-green, formerly used by miniature painters, was prepared by maceration, the fluid being left to putrefy, when chalk or alum was added.
• Iris versicolor, or blue flag, is indigenous to North America, and yields "iridin," a powerful hepatic stimulant.
• Iris xiphium, the Spanish iris and
• Iris xiphioides, the English iris. Despite the common name of I xiphioides, both are of Spanish origin, and have very showy flowers, so they are popular with gardeners and florists. They are among the hardier bulbous irises, and can be grown in northern Europe. They require to be planted in thoroughly drained beds in very light open soil, moderately enriched, and should have a rather sheltered position. Both these present a long series of beautiful varieties of the most diverse colours, flowering in May, June and July, the smaller Spanish iris being the earlier of the two.
• I. reticulata and I. persica, both of which are fragrant, are also great favourites with florists.
• The beautiful Japanese I. laevigator (rabbitear iris) is of comparatively modern introduction, and though of a distinct type h equally beautiful with the better-known species. The outer segmenu are rather spreading than deflexed, forming an almost circular flower which becomes quite so in some of the very remarkable duple varietics, in which six of these broad segments are produced instead of three. Of this too there are numberless varieties cultivated undei names. They require a sandy peat soil on a cool moist subsoil.
• The Douglas Iris, I. douglasiana, is a common wildflower of the coasts of California and southern Oregon.

Includes material edited from a 1911 encyclopedia

6 External links

• A web site devoted to Irises, by David Payne-Joyce; includes plates from Dykes (1913).
• The American Iris Society
• Treatment of Irises in the online Flora of North America

7 References

• Dykes, W. R. (1913). The genus Iris. Cambridge: Cambridge University Press.
• Rodionenko, G. I. (1961). The genus Iris L.. Moscow and Leningrad.