Wetland trees live in swamps and forested wetlands. These trees are more tolerant of high water tables and submerged roots than dryland species. Indiana wetland trees include green ash, black gum, hackberry, bitternut and shellbark hickory trees, pecan, persimmon, serviceberry, sweetgum and sycamore trees. A variety of oaks can also live in poorly drained soils. These include bur, cherrybark, pin, shumard, swamp chestnut and swamp white oaks. According to the U.S. Department of Agriculture, cherrybark oak and pecan do best in warmer parts of Indiana, south of U.S. Highway 40.
Shrubby plants grow in shrub wetlands and similar environments. These lowland plants tolerate a range of poorly through well drained soils and provide food for deer, rabbits, pheasants, grouse, turkeys and other wildlife. Indiana shrub wetlands include buttonbush, choke cherry, black chokeberry, elderberry, highbush cranberry, nannyberry, ninebark, spicebush, some Spirea species, wild sweet crabapple and winterberry. Wilted buttonbush leaves may be toxic for livestock, and should be kept away from browsing cattle, horses and sheep. Several dogwoods also grow in Indiana wetlands, including alternate leaf, gray, red-osier, rough leaved and silky dogwood.
Grasses and grass-like plants can be found in Indiana's wet meadows. Canada blue joint grass, fowl manna grass and prairie cordgrass all survive in somewhat to very poorly drained soils. Switchgrass and Virginia wildrye do better in poorly to well drained soils, and will die if the soil gets too wet. Wild rice, by comparison, survives in very poorly to poorly drained soils, and does poorly if conditions are too dry. It prefers to grow directly in shallow water.
A wide range of flowers inhabit wet meadows, shallow water marshes and even open water wetlands in Indiana. These include broadleaf arrowhead, New England, flat topped and swamp asters, bottle gentian, cardinal flower and tall coneflower. Irises grow well in very poorly to poorly drained soils, while joe-pye-weed does best in slightly wetter conditions. Wild celery, smartweed, sedge, sago pondweed, bur reed, nodding bur marigold and swamp milkweed can also be found in the wetlands of Indiana.