thistle vs wren

thistle

noun
  • The Order of the Thistle, or membership thereof. 

  • This plant used as a charge. 

  • Any of several perennial composite plants, especially of genera Cirsium, Carduus, Cynara, or Onopordum, having prickly leaves and showy flower heads with prickly bracts. 

  • This plant seen as the national emblem of Scotland. 

wren

noun
  • Any member of a mainly New World passerine bird family Troglodytidae; a true wren. 

  • Troglodytes troglodytes (Eurasian wren, type species and sole Old World species of the family Troglodytidae). 

  • Any small bird of similar appearance to a true wren, such as a fairywren or scrubwren. 

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