sago palm vs tapioca

sago palm

noun
  • Any palm or palmlike plant which yields sago, especially Metroxylon sagu and Cycas revoluta (a gymnosperm not closely related to palm trees). 

tapioca

noun
  • The cassava plant, Manihot esculenta, from which tapioca is derived; manioc. 

  • A starchy food made from the cassava plant, used in puddings. 

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