Iris versicolor, Northern Blue Flag

 
This native iris is one of the stalwarts of the water's edge, wetlands, rain gardens, and even will do well in moist garden soil. Handles competition well, like many wetland edge plants do. Plant with Cardinal Flower, Blue Lobelia, Sneezeweed, New England Aster, and Bog Goldenrod.

Blooms: pale lavender-blue purple with yellow-green throat, late May into July 

Height: leaves up to 3 feet tall, blooms 2 to 3 foot stems

Conditions: sun to pt sun, wet to moist-medium soils