blackcap vs salmonberry

blackcap

noun
  • Whitebark raspberry (Rubus leucodermis). 

  • A small Old World warbler, Eurasian blackcap (Sylvia atricapilla), which is mainly grey with a black crown. 

  • An apple roasted until black, to be served in a dish of boiled custard. 

salmonberry

noun
  • The fruit from this bush, similar in appearance and texture to the blackberry and raspberry. 

  • A bush, Rubus spectabilis, found on the Pacific coast of North America. 

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