iris, common name for members of the genus Iris of the Iridaceae, a family of perennial herbs that includes the crocuses, freesias, and gladioli. The family is characterized by thickened stem organs (bulbs, corms, and rhizomes) and by linear or sword-shaped leaves—small and grasslike in the crocuses and blue-eyed grasses. It is widely distributed over the world except in the coldest regions and is most abundant in S Africa and in tropical America. Almost all of the family's 90-odd genera include commercially valuable ornamentals. The iris family is closely related to the lily and amaryllis families, differing from them in having three stamens rather than six. The cultivated irises (genus Iris ), freesias (genus Freesia ), and gladioli (genus Gladiolus ) show a wide variety of colors in their large, usually perfumed blossoms; they are mostly hybrids of Old World species. The many species of wild iris are most common in temperate and subarctic regions of North America, where they are often called flags, or blue flags. The fleur-de-lis is thought to have been derived from the iris, and the flower of the Greek youth Hyacinth may have been an iris. Orrisroot, a violet-scented flavoring used in dentifrices, perfumes, and other products, is prepared from the powdered rhizomes of several European species of iris. The freesias, native to S Africa, characteristically bear their blossoms on a horizontal extension of the stem. The crocuses (genus Crocus ), which usually bear a single yellow, purple, or white blossom, are native to the Mediterranean area and to SW Asia. One species, saffron, is cultivated commercially for a yellow dye made from the pollen; the unrelated meadow saffron or autumn crocus and the wild crocus or pasqueflower belong to the lily and buttercup families respectively. Other members of the family found in the United States are the blue-eyed grasses (genus Sisyrinchium ) with small clusters of blue, white, or purplish flowers, ranging from Canada to Patagonia, and the celestial lily (genus Nemastylis ) with pairs of blue flowers, ranging from the Kansas prairies to Tennessee and Texas. Irises are classified in the division Magnoliophyta, class Liliopsida, order Liliales, family Iridaceae.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.