Christmas berry vs black alder winterberry

Christmas berry

noun
  • Synonym of spiceberry (“plant or its berry”) 

  • Synonym of toyon (“plant or its berry”) (Photinia arbutifolia, syn. Heteromeles arbutifolia) 

black alder winterberry

noun
  • A deciduous holly shrub, Ilex verticillata, native to eastern North America, growing best in moist circumstances. 

How often have the words Christmas berry and black alder winterberry occurred in a corpus of books? (source: Google Ngram Viewer )