bog bilberry vs highbush blueberry

bog bilberry

noun
  • A shrub native of the cool temperate areas of northern hemisphere, Vaccinium uliginosum, and the berry of that shrub. 

highbush blueberry

noun
  • The common species of blueberry, Vaccinium corymbosum, grown for its fruit. 

How often have the words bog bilberry and highbush blueberry occurred in a corpus of books? (source: Google Ngram Viewer )