batata vs cassava

batata

noun
  • sweet potato (plant) 

  • sweet potato (foodstuff) 

cassava

noun
  • Tapioca, a starchy pulp made with manioc roots. 

  • Manioc (Manihot esculenta), a tropical plant which is the source of tapioca. 

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