Parry's oatgrass is a western prairie bunchgrass with yellow-green leaves and paper glumes around the grass flowers. Grass flowers such as those of Parry's oatgrass are spikelets, with 2 empty bracts near the bottom called glumes. Just above the glumes are the flowers, which are generally enclosed between two bract-like structures called the palea and lemma. The lemma of Parry's oatgrass has a bristle sticking from it called an awn and this awn has a flattened base.
If you look closely at the leaf sheaths of Parry's oatgrass you will see little tiny hairs near the collar of the grass. The collar is where the leaf seems to attach to the grass stem.