Notice: Atrium is currently undergoing maintenance. During this time, some or all images may not be displayed.

Family: Iridaceae

Kingdom: Plantae Rank: Family Parent: Liliales Status: Valid

Common Names:

  • IRIS FAMILY - English, United States of America

Morphological Description

Family Recognition in the Field: Herbs with distichous leaves and flowers subtended by bracts, with a 6-parted, petaloid perianth, 3 stamens, and a 3-celled inferior ovary; the somewhat similar monocot families with petaloid perianths previously placed in the Liliaceae (e.g., Cronquist 1988) have 6 stamens and a superior or inferior ovary.

Diagnosis: Perennial or rarely annual herbs from fibrous roots or a bulb, corm, or rhizome; leaves mostly basal or alternate, distichous (2-ranked), the stem and leaves together often having a flattened appearance; leaf bases sheathing the stem; leaf blades oriented edgewise to the stem, laterally compressed (unifacial) or flat, pleated, or concave, or with prominent midrib; inflorescences various; flowers arising from a spathe of bracts; perianth parts 6, in 1 or 2 whorls, similar or of 2 different sizes or shapes; stamens 3, opposite the outer perianth whorl; pistil 1; style branches filiform or nearly so or petaloid in Iris; ovary inferior; fruit a capsule.


Notes: A medium-large family (1,810 species in 92 genera—Goldblatt 2002a) of nearly worldwide distribution (but rare in tropical lowlands), especially s Africa, e Mediterranean, and Central and South America. The center of taxonomic diversity and endemism for the Iridaceae is Africa, with ca. 950 species endemic to s Africa (Bernhardt & Goldblatt 2000). Both morphological and molecular studies indicate the family is monophyletic (e.g., Goldblatt 1990; Rudall 1994; Chase et al. 1995a; Souza-Chies et al. 1997; Fay et al. 2000; Reeves et al. 2001) and place it in the Asparagales. The family includes many important ornamentals in addition to Iris, including Belamcanda (LEOPARD-LILY), Crocus, Freesia, Gladiolus, Ixia (CORN-LILY), and Tigridia (TIGERFLOWER). The world’s most expensive spice, saffron, important as a food coloring, is obtained from the stigmas of Crocus sativus L. (subclass Liliidae—Cronquist; order Asparagales—APG II)