In Missouri, crested iris occurs naturally only in our southeastern counties. If you’re already familiar with irises, this is an easy identification: in addition to the distinctive color pattern, this iris does not exceed 12 inches in height, and the sepals (“falls”) have conspicuous, bumpy crests.
Blooms April–May.
Leaves basal, to 12 inches long, flat, bladelike, erect.
Flowers single or 2 per stem; sepals 3, petal-like, spreading or arching downward, with a noticeable, fringed, yellow crest bordered with a white area, outlined with purple, the rest of sepal blue to light purple (rarely white); petals 3, slightly smaller than sepals, blue to light purple (rarely white).
Fruits capsules ½ to ¾ inches long, egg-shaped, 3-angled.
Similar species: With their lovely, fragrant flowers and handsome foliage, irises are a longtime favorite genus for gardeners. Eleven species of irises have been recorded as either native or as surviving outside of cultivation (naturalized) in Missouri. For more information about Missouri’s irises, native and introduced, visit their group page.
Height: Less than 12 inches.
Scattered in the eastern portion of the Ozarks and locally to the east in Scott County. A population in Franklin County resulted from introduced plants.
Habitat and Conservation
Occurs in mesic to dry upland forests, bluff tops and ledges, and sandy stream banks, often on chert or dolomite substrates.
Note that in other states, this species also commonly occurs on sandstone and other acidic substrates. This species occurs in much of the eastern United States.
Status
Native Missouri wildflower. Like other native irises, people sometimes cultivate it in native wildflower gardens. Never dig plants from natural populations. Acquire them from ethical native wildflower nurseries.
Human Connections
Irises are beautiful flowers and rival orchids for their floral colors and interesting shape. Like other native irises, this species is sometimes cultivated in native wildflower gardens. Never dig plants from natural populations. Acquire them from ethical native wildflower nurseries.
Ecosystem Connections
Irises and other plants that grow along streams and in other places prone to flooding help to hold the soil against erosion.
The so-called signal (the conspicuous yellow and/or white patch at the throat of the sepal) helps pollinating bees know where to seek nectar from the flowers. The interesting flower structure forces bees to crawl into the flower beneath the flat, petal-like style arm. As it pushes beneath this structure, the bee rubs previously collected pollen from its back onto a flaplike stigmatic lip, fertilizing the flower. Moving further into the flower, the bee rubs new pollen onto its back.
