black raspberry vs whitebark raspberry

black raspberry

noun
  • The fruit of any of these species. 

  • A plant belonging to either of two closely related species, Rubus leucodermis or Rubus occidentalis, both native to North America. 

  • Rubus coreanus, native to Korea, Japan, and China 

whitebark raspberry

noun
  • The dark purple composite fruit of this plant, similar to a raspberry. 

  • A deciduous, viny shrub (Rubus leucodermis) with a pale, whitish bark. 

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