bloodwort vs bloody dock

bloodwort

noun
  • Any of the Haemodoraceae, a family of flowering plants some of whose roots contain a red dye. 

  • Rumex sanguineus, bloody dock, wood dock, bloody-veined dock. 

  • Sanguinary, common yarrow, Achillea millefolium. 

  • Capsella bursa-pastoris, shepherd's purse. 

  • The plant bloodroot, Sanguinaria canadensis. 

  • Various species in the genus Sanguisorba, burnet. 

bloody dock

noun
  • A herb named for its characteristic red or purple veins, used in moderate amounts in salads and as ornamental vegetable, Rumex sanguineus. 

How often have the words bloodwort and bloody dock occurred in a corpus of books? (source: Google Ngram Viewer )