Umbrella Plant
WordNet
noun
(1) African sedge widely cultivated as an ornamental water plant for its terminal umbrellalike cluster of slender grasslike leaves
(2) Late blooming perennial plant of shale barrens of Virginia having flowers in flat-topped clusters
(3) Rhizomatous perennial herb with large dramatic peltate leaves and white to bright pink flowers in round heads on leafless stems; colonizes stream banks in the Sierra Nevada in California