cornflower vs wild endive

cornflower

adj
  • Of a blue colour, as that of the cornflower; cornflower blue. 

noun
  • Cornflower blue. 

  • A plant of the species Cichorium intybus. 

  • A small annual plant in the family Asteraceae, Centaurea cyanus, usually with bushy blue flowers which grows natively in European cornfields (i.e. wheatfields). 

wild endive

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