Masticophis flagellum vs coachwhip

Masticophis flagellum

coachwhip

noun
  • A long whip used by the driver of a horse-drawn coach. 

  • Masticophis flagellum, a colubrid snake of North America. 

  • Fouquieria splendens (ocotillo). 

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