May blossom vs quickthorn

May blossom

noun
  • A species of flower-bearing hawthorn with edible berries, Crataegus monogyna. 

quickthorn

noun
  • The may-tree, any species of Crataegus or the species Crataegus monogyna. 

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