The Collaborative International Dictionary of English v.0.48:

Bloodflower \Blood"flow`er\, n. [From the color of the flower.]
   (Bot.)
   A genus of bulbous plants, natives of Southern Africa, named
   H[ae]manthus, of the Amaryllis family. The juice of
   H[ae]manthus toxicarius is used by the Hottentots to poison
   their arrows.
   [1913 Webster]