What shrubs are suitable for a wet area of my yard? I live in the Midwest.

Shrubs tolerant of moist to wet soils:

Chokeberry
Buttonbush
Summersweet
Tartarian Dogwood
Silky Dogwood
Red Twig Dogwood
Inkberry
American Holly
Winterberry
Virginia Sweetspire
Leycothe
Spicebush
Alabama Snow-Wreath
Coast Azalea
Pinxterbloom Azalea
Swamp Azalea
Pussywillow
Rosemary Willow
Rosegold Pussywillow
Purpleosier Willow
Japanese Fantail Willow
American Elder
American Snowbell
Highbush Blueberry
Yellowroot
Dusty Zenobia

Here is a link to a shrub selector that may be of some help:

http://www.urbanext.uiuc.edu/shrubselector/