Michigan holly vs inkberry

Michigan holly

noun
  • American winterberry, Ilex verticillata. 

inkberry

noun
  • Ilex verticillata, American winterberry 

  • Scaevola plumieri, a fan flower 

  • Any plant of the genus Phytolacca, especially Phytolacca americana, the pokeweed. 

  • Ilex glabra (winterberry, gallberry) 

How often have the words Michigan holly and inkberry occurred in a corpus of books? (source: Google Ngram Viewer )