Flowering rush (Butomus umbellatus) resembles a large sedge, with upright foliage that grows in shallow water, though it may also grow submerged. Its leaves have a triangular cross-section with a twist toward the tip. The easiest way to identify it is by the flowers, which are light pink with 6 petals and grow in clusters.
Flowering rush grows around lake shores, ponds, wetlands, streams, and in drainage ditches.
This species can spread rapidly, choking out other native species. It can also weaken shorelines and cause a disruption in recreational activities such as boating or swimming.