foxberry vs mountain cranberry

foxberry

noun
  • The plant cowberry or lingonberry, Vaccinium vitis-idaea. 

  • The berry of this plant. 

mountain cranberry

noun
  • The cowberry, Vaccinium vitis-idaea 

  • The mountain bearberry, Arctostaphylos alpina 

How often have the words foxberry and mountain cranberry occurred in a corpus of books? (source: Google Ngram Viewer )