The Collaborative International Dictionary of English v.0.48:

Bloodwort \Blood"wort`\, n. (Bot.)
   A plant, Rumex sanguineus, or bloody-veined dock. The name
   is applied also to bloodroot (Sanguinaria Canadensis), and
   to an extensive order of plants (H[ae]modorace[ae]), the
   roots of many species of which contain a red coloring matter
   useful in dyeing.
   [1913 Webster]