Western Wheatgrass (Agropyron smithii); photo by Matt Lavin on Flickr (use permitted with attribution / share alike).
Official State Grass of North Dakota
North Dakota designated western wheatgrass (Agropyron smithii) as the official state grass in 1977. The North Dakota Chapter of the Society for Range Management initiated the process for adopting an official state grass. All State Grasses & Plants
A tough native prairie grass that once covered nearly the entire state, western wheatgrass was recognized for "its adaptability to soil conditions, its performance record for hay and pasture, and its role in range management as a species found in all the state's counties" (quote from ND.gov). "Western wheat grass" is also a state symbol of South Dakota.