blackcap vs whitebark raspberry

blackcap

noun
  • Whitebark raspberry (Rubus leucodermis). 

  • A small Old World warbler, Eurasian blackcap (Sylvia atricapilla), which is mainly grey with a black crown. 

  • An apple roasted until black, to be served in a dish of boiled custard. 

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 blackcap and whitebark raspberry occurred in a corpus of books? (source: Google Ngram Viewer )