damson vs sloe

damson

noun
  • The edible fruit of this tree. 

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

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

sloe

noun
  • The tree Prunus spinosa. 

  • The small, astringent, wild fruit of the blackthorn (Prunus spinosa). 

  • Any of various other plants of the genus Prunus, as a shrub or small tree, Prunus alleghaniensis, bearing dark-purple fruit. 

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