Blue flag iris - Iris virginica var. shrevei

Features:  Delicate blue-violet flowers rise from clumps of sword-shaped basal leaves. They are pollinated by bumblebees and also attract butterflies and other insects. Several types of caterpillar feed on the foliage.

Light: Full or partial sun

Soil: Wet to moist; good for the rain garden

Height: 2-3 feet

Blooms:  May-June

See more information and photos at Illinois Wildflowers and USDA Plants Database

Photo credit: Illinois Wildflowers