American winterberry vs pokeweed

American winterberry

noun
  • Ilex verticillata, a species of holly native to eastern North America in the United States and southeast Canada, from Newfoundland west to Ontario and Minnesota, and south to Alabama. 

pokeweed

noun
  • A poisonous North American plant, Phytolacca americana, with reddish stems, broad leaves, clusters of white flowers, and dark purple berries. 

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