manroot vs wild potato-vine

manroot

noun
  • A flowering plant in the gourd family (Cucurbitaceae), genus Marah, native to western North America. 

  • Ipomoea leptophylla 

  • Ipomoea pandurata 

wild potato-vine

How often have the words manroot and wild potato-vine occurred in a corpus of books? (source: Google Ngram Viewer )