大扁雀麦（学名：Bromus catharticus），又名扁穗雀麦，为禾本科雀麦属下的一个种。

Bromus catharticus is a species of brome grass known by the common names rescuegrass, grazing brome, prairie grass, and Schrader's bromegrass.

It is native to South America but it can be found in other places, including Europe, Australia and North America, as an introduced species. It is an annual or perennial grass growing up to a meter in height. The inflorescence is made up of spreading spikelets, the upper ones erect and the lower ones nodding or drooping. Each spikelet is very flat and pointed, the fruits tipped with short awns.