horsemint vs lemon mint

horsemint

noun
  • A coarse American plant of the mint family (Monarda punctata). 

  • An aromatic plant of the mint family, Agastache urticifolia. 

  • Wild mint (Mentha sylvestris, now Mentha longifolia). 

lemon mint

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