canafistula vs golden rain tree

canafistula

noun

  • The flowering plant Cassia fistula, the golden shower tree. 

golden rain tree

noun

  • Any plant of genus Koelreuteria, especially Koelreuteria paniculata. 

  • Cassia fistula 

How often have the words canafistula and golden rain tree occurred in a corpus of books? (source: Google Ngram Viewer )