Chasmanthium latifolium, known as Northern Wood-Oats, Inland Sea Oats, Northern Sea Oats, and River Oats is a grass native to the central and eastern United States, Manitoba, and northeastern Mexico; it grows as far north as Pennsylvania and Michigan. It is a native, cool-season perennial grass common in bottomlands, stream valleys, and other moist places. It grows from stout rhizomes and forms loose colonies. The open, nodding, flattened flower and seed clusters are distinctive.
It makes a lovely accent planting in the proper location, growing to 2.5' to 3' tall with graceful, flattened seed heads that flutter in the wind. They provide birds and mammals with food and serve as a host plant for some butterflies. River oats is a bright green during the spring and summer, becoming a coppery-yellow in the fall.