cheatgrass (bromus tectorum) with flowers on a drooping panicle : (pix sanjiv shukla)

bromus tectorum downy brome drooping cheatgrass poaceae gramineae flowering plant winter annual grass invasive crop weed ecosystem noxious rapid growth seed ubiquitous natural grassland cultivated pasture herbicide stem smooth slender leaves hairy sheath flower inflorescence spikelets lawn selfpollinating fibrous root system widespreading lateral moisture europe asia australia zealand iceland greenland north america