Helleborus species

The bufadienolides occur in plants as well as animals, but only in plants are they in the form of glycosides. Their 3-hydroxyl group is attached lo glucose, rhamnose, or thevetosc. Hellebrigenin (Fig. 2). which is also known as bufotalidin. occurs in the rhizomes of the Christmas rose and other Helleborus species in the form of a rhamnoside. Bufadienolides have so far been found in plants in only two families, the buttercup and the lily family. 

Many plants containing cardioactive glycosides are widely grown as ornamentals and must be considered toxic and treated with due care and respect. These include Digitalis species, Convallaria majalis, Helleborus species, and oleander (Nerium oleander, Apocynaceae). 

---