The bladderwort is a free-floating water plant with submerged delicate leaves. The flowers are bright yellow. The most distinctive underwater features are the small bladder-like traps. Because of the lower water pressure inside the trap than outside, when small invertebrates, or even tiny fish, trigger the trap door they are carried into the trap as the water rushes in. Enzymes are secreted to digest the prey, which provide the plant with nutrients.
This plant can be found throughout the Northern Hemisphere floating freely in the shallow water of lakes, ponds, marshes and rivers or loosely attached to the sediment. The presence of bladderwort generally indicates an abundance of microscopic life and a healthy aquatic environment.