great bulrush
nounDefinition of great bulrush
: any of several large plants of the genus Scirpus: such as
a
: a tall Eurasian sedge (S. lacustris) with naked terete stems and a compound umbel of numerous capitate spikes
b
: a bulrush (S. validus) of tropical America and southern U.S. with a stout scaly reddish rhizome, thick pliable culm, and spikelets in close fascicles or glomerules
also
: a bulrush chiefly of northern North America that is a variety (S. validus creber) of the above distinguished especially by lax panicles