pocan vs pokeberry

pocan

noun
  • The poke, Phytolacca americana (formerly Phytolacca decandra). 

pokeberry

noun
  • Synonym of pokeweed (the plant Phytolacca americana or its dark red or purple fruit). 

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