umbrella plant (Noun) — 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.
umbrella plant (Noun) — Late blooming perennial plant of shale barrens of Virginia having flowers in flat-topped clusters.
umbrella plant (Noun) — African sedge widely cultivated as an ornamental water plant for its terminal umbrellalike cluster of slender grasslike leaves.