arrowroot vs obedience plant

arrowroot

noun
  • A starchy substance obtained from the rhizomes of an arrowroot plant used as a thickener. 

  • Maranta arundinacea from the Marantaceae family, a large perennial herb native to the Caribbean area with green leaves about 15 centimeters long. 

  • Usually preceded by an attributive word: some other plant whose rhizomes are used to prepare a substance similar to arrowroot (sense 3), such as Zamia integrifolia (Florida arrowroot) or Pueraria montana var. lobata (Japanese arrowroot or kudzu). 

obedience plant

How often have the words arrowroot and obedience plant occurred in a corpus of books? (source: Google Ngram Viewer )