goat's-beard vs hawthorn tree

goat's-beard

noun
  • A woodland plant of the family Rosaceae, Aruncus dioicus. 

  • A yellow-flowered Eurasian plant, of the genus Tragopogon. 

hawthorn tree

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

How often have the words goat's-beard and hawthorn tree occurred in a corpus of books? (source: Google Ngram Viewer )