Irises (Iris) — identification, habitat & look-alikes

Irises include familiar garden plants and wildflowers native to wetlands, meadows, and mountains across the United States. A typical flower has three outer parts that spread or droop and three inner parts that stand more upright, but the genus is remarkably varied.

In this group

northern blue flagIris versicolor

This wetland iris is native across much of the Northeast and upper Midwest. Its blue-purple flowers have a yellow-and-white signal on the .

southern blue flagIris virginica

This native iris grows in marshes and wet ground in the eastern and southeastern United States. Its leaves and flower stalks rise from dense clumps.

western blue flagIris missouriensis

This species grows in moist meadows and streamside areas of the West. Pale blue to violet flowers rise above narrow leaves.

yellow irisIris pseudacorus

This European wetland species has escaped gardens across much of the country. Its yellow flowers and tall fans of leaves make it easy to notice, but it can form invasive stands.

bearded irisIris × germanica

This old hybrid is one of the most familiar garden irises. A fuzzy beard runs along the center of each hanging fall.

Appearance

Growth form: Most are that return from , although some groups grow from bulbs.
Flowers: Blue, purple, yellow, white, and many cultivated color combinations occur. Some species have a fuzzy beard or raised crest on each fall, while others have a smooth fall.
Fruit: The fruit is a dry that opens to release seeds.
How to recognize it: Look for flat, sword-shaped leaves arranged in fans and flowers whose three outer falls differ from the three inner . Broad, petal-like branches of the flower’s female part partly hide the pollen-bearing parts.

Look-alikes

sweet flagsAcorus

Sweet flags have irislike sword-shaped leaves, but their small greenish flowers crowd into a narrow spike. Irises have large, separate flowers.

Why they get mixed upBoth can grow at the water’s edge and have long upright leaves.

Where it lives

Typical habitats: wetlands and shorelines
meadows and mountain slopes
gardens
Range: The genus occurs across the Northern Hemisphere. North America has native blue flags in the East, western species in mountain and coastal regions, and introduced garden irises.
Preferred conditions: Moisture needs vary by species. Some irises grow in standing water or saturated soil, while many bearded garden irises need sun and well-drained ground.

Growing it

Propagation: Wild species reproduce by seed, and many also expand through branching rhizomes. Garden forms are commonly divided after flowering.

Name and classification

Group name: “Irises” usually refers to genus Iris, although a few unrelated ornamentals also carry iris in their common names. “Blue flag” is used for several wetland Iris species rather than one plant everywhere.
Varieties and forms: Garden irises include many bearded and beardless groups and many named cultivars. A cultivated plant may not match the appearance of any single wild species.

Culture and stories

Culture and stories: The genus name refers to Iris, the Greek rainbow goddess, fitting the wide range of flower colors.

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