common alder vs possumhaw

common alder

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

possumhaw

noun
  • American winterberry, Ilex verticillata. 

  • Deciduous Holly, Ilex decidua. 

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