cassava vs yucca

cassava

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

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

yucca

noun
  • Any of several evergreen plants of the genus Yucca, having long, pointed, and rigid leaves at the top of a woody stem, and bearing a large panicle of showy white blossoms. 

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