skokeberry vs white alder

skokeberry

noun
  • A pokeberry; a pokeweed (the plant Phytolacca americana or its dark red or purple fruit). 

white alder

noun
  • American winterberry (Ilex verticillata). 

  • Grey alder (Alnus incana) 

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