dragon arum vs green dragon

dragon arum

noun
  • Dracunculus vulgaris, a species of aroid. 

green dragon

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

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

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

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