Federal Noxious Weed. Floating aquatic fern with leaves that become compressed into chains in older plants. Leaves: about ½-1½ in. long; oval, folded, and covered with arching hairs.

Not known to exist in Nebraska. Found in most southern U.S. states.

Poses a serious threat to lakes, ponds, streams, rivers and other freshwater wetlands, and cultivated rice fields. It grows rapidly and spreads across water surfaces, forming dense floating mats that cut off light to other aquatic plants, reduces oxygen content and degrades water quality for fish and other aquatic organisms.