The majority of Bromus spp. (Brome Grasses) have been introduced from Eurasia (either deliberately or accidentally). Many of these species are weedy and aggressive, and Smooth Brome is no exception. It can be distinguished from other Brome Grasses by the absence of awns on its spikelets (rarely with awns up to 2 mm. long); almost all other Brome Grasses in Illinois have spikelets with conspicuous awns (greater than 2 mm. long). An exception is Bromus catharticus (Rescue Grass), which has been collected only once in Champaign County, Illinois. Rescue Grass is occasionally planted in the southern states as a source of winter forage. It is an annual grass with leaf blades up to ¼" across. In contrast, Smooth Brome is a perennial grass with leaf blades greater than ¼" across. Another common name of Bromus inermis is Hungarian Brome.