Vaccinium vitis-idaea vs cowberry

Vaccinium vitis-idaea

cowberry

noun
  • A shrub native to the cool temperate areas of the Northern Hemisphere (Vaccinium vitis-idaea). 

  • The berry of this shrub. 

How often have the words Vaccinium vitis-idaea and cowberry occurred in a corpus of books? (source: Google Ngram Viewer )