Korean morning glory vs jimsonweed

Korean morning glory

jimsonweed

noun
  • A poisonous plant of the Datura stramonium species, part of the nightshade (Solanaceae) family. A hallucinogen occasionally ingested by those looking for a cheap high. 

  • Any poisonous plant of the genus Datura. 

How often have the words Korean morning glory and jimsonweed occurred in a corpus of books? (source: Google Ngram Viewer )