bog bilberry vs lingonberry

bog bilberry

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

lingonberry

noun
  • A berry-bearing shrub, Vaccinium vitis-idaea, native to the cool temperate areas of the Northern Hemisphere. 

  • The berry of this shrub. 

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