ironwort vs mountain tea

ironwort

noun
  • A herb of several species in the genus Sideritis, formerly believed to heal sword cuts. 

  • Galeopsis ladanum, red hemp-nettle. 

mountain tea

noun
  • The ironwort plant (of genus Sideritis) 

  • An infusion of the leaves of this plant 

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