Aaron's rod vs coachwhip

Aaron's rod

noun
  • A rod-shaped molding decorated with an entwined snake, and sometimes leaves, vines, and/or scrolls. 

  • Hylotelephium telephium (syn. Sedum telephium; orpine, livelong, or live-forever). 

  • Goldenrod, the Solidago genus of North American plants with yellow flowers. 

  • Verbascum thapsus, the great mullein, common mullein, or hag-taper. 

coachwhip

noun
  • Masticophis flagellum, a colubrid snake of North America. 

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

  • Fouquieria splendens (ocotillo). 

How often have the words Aaron's rod and coachwhip occurred in a corpus of books? (source: Google Ngram Viewer )