Bulrush

Bulrush, any of a genus (Scirpus) of sedges growing in water or marshes, up to 6 ft (2 m) high, with narrow leaves and spiky flowers. Bulrushes grow from rhizomes, which help to anchor debris accumulating in the water, hastening the natural drying out of swamps. Bulrushes are used by Peruvian Indians to make boats.