accentor vs selfheal

accentor

noun
  • Any bird of the Eurasian genus Prunella, such as the dunnock. 

selfheal

noun
  • A small, herbaceous European plant with blue-violet flowers from any species of genus Prunella. 

  • Especially, Prunella vulgaris. 

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