devil's trumpet vs green dragon

devil's trumpet

noun
  • jimsonweed (Datura spp.) 

green dragon

noun
  • Used other than figuratively or idiomatically: see green, dragon. 

  • A tincture of cannabis, typically made by soaking the flowers, leaves, or stems in ethyl alcohol. 

  • Any of several plants in the family Araceae, including the North American species Arisaema dracontium and the Asian genus Pinellia. 

How often have the words devil's trumpet and green dragon occurred in a corpus of books? (source: Google Ngram Viewer )