2a tall rushlike water plant of the sedge family. Native to temperate regions of the northern hemisphere, it has been widely used for weaving and is grown as an aid to water purification in some areas.
Scirpus lacustris, family Cyperaceae
3(in biblical use) a papyrus plant.
late Middle English: probably from bull1 in the sense 'large or coarse', as in words such as bullfrog
Bulrush can also be spelled bullrush, with a double l: both are correct.