Canna edulis vs achira

Canna edulis

achira

noun
  • The edible rhizome of this plant. 

  • Canna indica (syn. Canna edulis), similar to arrowroot: the canna lily, the seeds of which yield a purple dye. 

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