black alder vs common alder

black alder

noun
  • A tree (Alnus glutinosa), of many practical uses, growing in moist conditions in Europe. 

  • Wood or other product of the tree. 

  • American winterberry, Ilex verticillata. 

common alder

noun
  • A tree native to much of Europe and neighboring Africa and Asia (Alnus glutinosa). 

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