cornflower vs strawflower

cornflower

noun
  • A plant of the species Cichorium intybus. 

  • Cornflower blue. 

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

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

strawflower

noun
  • Any of many Australian plants of the genus Xerochrysum, especially Xerochrysum bracteatum, having deep yellow flowers than can be readily dried. 

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