bullace vs damson

bullace

noun

  • A small European plum (Prunus interstitia, syn. Prunus domestica subsp. insititia). 

  • The bully tree. 

damson

noun

  • A subspecies of plum tree, Prunus domestica subsp. insititia, native to Eurasia. 

  • The edible fruit of this tree. 

adj

  • The color of the fruit of this tree, a very deep purple. 

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