hawthorn tree vs whitethorn

hawthorn tree

noun
  • A tree of the genus Crataegus, having small, apple-like fruits and thorny branches. 

whitethorn

noun
  • Bursaria spinosa, a small Australian shrub. 

  • Ceanothus leucodermis, chaparral whitethorn, a shrub in the family Rhamnaceae. 

  • Crataegus monogyna, a hawthorn species native to Europe, northwest Africa and western Asia. 

  • Vachellia constricta, formerly Acacia constricta, whitethorn acacia, a shrub in the family Fabaceae. 

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