Perhaps you should try some spelling variations:
"prairie corn grass" » "prairie cord grass", "prairie city grass", "prairie vole grass", "prairie corn grains", "prairie corn grain"
"prairie town grass" » "prairie vole grass", "prince town grass", "prairie cord grass", "prairie lawn grass", "prairie town gas", "prairie sown grasses"
"prairie dogs grass" » "prairie dog's grass", "prairie dogs glass"

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 corn grass") OR ((("prairie town grass") OR ("prairie dogs grass")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"prairie corn grass\") or (((\"prairie town grass\") OR (\"prairie dogs grass\"))))".
• Removing quotes may allow a broader search: (( prairie corn grass ) or ((( prairie town grass ) OR ( prairie dogs grass )))).
• Adding a wildcard symbol may retrieve word variants: (("prairie corn grass") or ((("prairie town grass") OR ("prairie dogs grass"))))*.