cloudberry vs salmonberry

cloudberry

noun
  • The fruit of these plants. 

  • A species of slow-growing bramble, Rubus chamaemorus. 

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