Real Dictionary

sedge
variable noun: Sedge is a plant that looks like grass and grows in wet ground.

sedge in American English
any of the plants of the sedge family often found on wet ground or in water, having usually triangular, solid stems, three rows of narrow, pointed leaves, and minute flowers borne in spikelets
designating a family (Cyperaceae, order Cyperales) of grasslike, monocotyledonous plants, including papyrus
noun: any rushlike or grasslike plant of the genus Carex, growing in wet places

sedge in British English
noun: any grasslike cyperaceous plant of the genus Carex, typically growing on wet ground and having rhizomes, triangular stems, and minute flowers in spikelets