blackcap raspberry vs salmonberry

blackcap raspberry

noun
  • Whitebark raspberry. 

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 raspberry and salmonberry occurred in a corpus of books? (source: Google Ngram Viewer )