mountain apple vs wax apple

mountain apple

noun
  • The Malay apple or pommerac (Syzygium malaccense). 

  • Used other than figuratively or idiomatically: see mountain, apple. 

wax apple

noun
  • the fruit of this plant 

  • a tropical plant, Syzygium samarangense, bearing an edible fruit 

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