bilberry vs lingonberry

bilberry

noun
  • The shrub of the above-mentioned plant. 

  • Vaccinium myrtillus, the wild European blueberry of the cowberry family. 

lingonberry

noun
  • The berry of this shrub. 

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

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