common alder vs white alder

common alder

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

white alder

noun
  • Grey alder (Alnus incana) 

  • American winterberry (Ilex verticillata). 

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