Perhaps you should try some spelling variations:
"prairie cord grass" » "prairie dogs grass", "prairie city grass", "prairie vole grass", "prairie corn grass", "prairie bird grass", "prairie cord graft"
"prairie corn grains" » "prairie town grains", "prairie dogs grains", "prairie city grains", "prairie corn grain", "prairie corn grass", "prairie carbon grains"

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (("prairie cord grass") OR ("prairie corn grains")).
• Removing quotes may allow a broader search: (( prairie cord grass ) or ( prairie corn grains )).
• Adding a wildcard symbol may retrieve word variants: (("prairie cord grass") or ("prairie corn grains"))*.