celandine vs swallow wort

celandine

noun

  • lesser celandine (Ficaria verna, formerly Ranunculus ficaria) 

  • Either of two not closely related flowering plants 

  • greater celandine (Chelidonium majus) 

swallow wort

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