Photo © Robert Bursik CLICK PHOTO FOR A LARGER IMAGE

Iris versicolor L.

Blueflag

Iridaceae (Iris family)

General description: Iris versicolor is an erect, evergreen perennial, 30-60(90) cm tall, from a stout underground rootstock. It has green to grayish-green narrow, flat, sword-shaped leaves 10-80 cm long and 1-3 cm wide. The stem leaves seldom equaling the inflorescence which is a compact, 2-4 flowered fascicle. Bracts of the inflorescence are papery or chaffy in texture, 3-6 cm long, and with the margins appearing to be much darker in color. The showy, violet-blue flowers have sepals 4-7 cm long and petals 2-5 cm long. The flowers have veins slightly darker than the ground color and are roughened at the base of the blade with minute bumps scarcely visible to the naked eye that form a dull greenish-yellow spot in live material.

Photo © Susan Bernatas CLICK PHOTO FOR A LARGER IMAGE

Field Identification Tips: Characteristics of the showy flowers and the leaves make the irises a distinctive group.

Phenology: June - August.

Similar Species: Iris missouriensis is the common and widespread native iris in Idaho. It differs in having leaves 5-12 mm wide and generally paler blue flowers. In addition, the seasonally moist meadows or other openings where it typically occurs are drier than the wetland habitats for I. versicolor. The large, showy flowers of many introduced/horticultural irises are bearded, a feature none of the native North American species have. Acorus calamus (sweet flag) is an introduced wetland species that has similar looking leaves. In flower it is easily differentiated.

Global Distribution: Eastern North America from Labrador to Virginia, west to Wisconsin, Ohio, Minnesota, and Manitoba. Disjunct in northern Idaho and perhaps elsewhere in the Pacific Northwest.

Habitat: Swamps, marshes, wet meadows, and along lakes and rivers.

Photo © Robert Bursik CLICK PHOTO FOR A LARGER IMAGE

Idaho Distribution: Known from the upper Priest Lake area in Bonner County.

References:

Anderson, E. A. 1936. The species problem in Iris. Annals of the Missouri Botanical Garden 23:457-469.