Sedge, any of afamily (Cyperaceae) of grasslike plants found in damp places worldwide in temperate regions. They have triangular, flattened or cylindrical stems, and the leaves arise from sheaths that enclose the stem. The flowers are in clusters grouped in a spikelet. True sedges have triangular stems. Some are used for making matting. Other sedges include the bulrushes (genus Scirpus), cotton grass (genus Eriophorum), and papyrus (Cyperuspapyrus).