cassava vs kumara

cassava

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

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

kumara

noun
  • A sweet potato. 

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