Monarda citriodora vs horsemint

Monarda citriodora

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). 

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