cowberry vs shinleaf

cowberry

noun
  • The berry of this shrub. 

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

shinleaf

noun
  • A perennial ericaceous herb (Pyrola elliptica) with a cluster of radical leaves and a raceme of greenish-white flowers. 

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