Lonicera involucrata vs twinberry

Lonicera involucrata

twinberry

noun
  • A North American species of honeysuckle, Lonicera involucrata. 

  • Its fruit, a bitter edible black berry containing several small seeds. 

How often have the words Lonicera involucrata and twinberry occurred in a corpus of books? (source: Google Ngram Viewer )