noun

1. any of a number of marsh plants (genus Scirpus) of the sedge family, having slender, round or triangular, solid stems tipped with brown spikelets of minute flowers
2. Brit. the cattail
3. popularly any aquatic plant resembling a bulrush, as the papyrus

Etymology: ME bulryshe < bol, stem (see bole) + rusche, rush