red rattle vs wood betony

red rattle

noun
  • Any of several plant species of the genus Pedicularis and others. 

  • Odontites vernus (red bartsia) 

  • Pedicularis palustris (marsh lousewort) 

  • Pedicularis flammea 

wood betony

noun
  • A North American perennial herb, Pedicularis canadensis, which is a partial root parasite and has been used in traditional medicine. 

How often have the words red rattle and wood betony occurred in a corpus of books? (source: Google Ngram Viewer )