Flowering rush is a non-native aquatic resembling a large sedge that grows along lake shores and slow moving water bodies. In Montana it was recorded in Flathead Lake in 1964 and has spread to Thompson Falls, Noxon Reservoir, Cabinet Gorge, portions of the Flathead River, and the Clark Fork River. Prolific growth in irrigation ditches reduces water availability, and dense stands in previously unvegetated areas inhibit boating, fishing and swimming. Minor disturbances cause the roots to fragment, providing long distance dispersal. At this time, control methods are limited. Hand digging has led to mixed results as rhizomes fragment easily, increasing dispersal. Studies on chemical control options are ongoing.