fir vs stone pine

fir

noun
  • Any pinaceous conifer of related genera, especially a Douglas fir (Pseudotsuga) or a Scots pine (Pinus sylvestris). 

  • A conifer of the genus Abies. 

  • Wood of such trees. 

stone pine

noun
  • A species of pine native of southern Europe, Pinus pinea. 

  • Swiss stone pine (Pinus cembra) 

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