cola vs kola

cola

noun
  • The kola plant, genus Cola, famous for its nut, or one of these nuts. 

  • A beverage or a drink made with kola nut flavoring, caramel and carbonated water. 

  • A cluster of buds on a cannabis plant. 

kola

noun
  • A tree, genus Cola, bearing large brown seeds ("nuts") that are the source of cola extract. 

  • A nut of this tree. 

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