cowberry vs cranberry

cowberry

noun
  • The berry of this shrub. 

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

cranberry

noun
  • The edible red berry of that shrub. 

  • A shrub belonging to the section Vaccinium sect. Oxycoccus of the genus Vaccinium. 

  • An intense red colour, like that of a cranberry 

adj
  • Of the intense red colour of a cranberry. 

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