partridgeberry vs twinberry

partridgeberry

noun
  • The berry of such a plant. 

  • lingonberry, Vaccinium vitis-idaea 

  • teaberry, Gaultheria procumbens 

  • squaw vine, Mitchella repens 

twinberry

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

  • A North American species of honeysuckle, Lonicera involucrata. 

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