Ilex decidua vs bearberry

Ilex decidua

bearberry

noun
  • Any of three dwarf shrubs of the genus Arctostaphylos, which principally grow in arctic and subarctic regions and bear edible berries. 

  • Arctostaphylos uva-ursi, the common bearberry. 

  • Arbutus menziesii. 

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