WordNet
broom grass
n. any of several grasses of the genus Andropogon; used in broom making
Wikipedia
Broom grass
Broom grass is a name used for different types of grass around the world.
In tropical Asia it refers to Thysanolaena maxima of the family Poaceae; a tall, <3m, grass which is used for making brooms.
In United States it refers to Andropogon glomeratus of the family Poaceae, a tall grass, growing to about 2m high.