Clematis viticella, Purple clematis, is a climbing plant belonging to the family of Ranuncolaceae, with bell-shaped flowers which consist of four purple or violet-blue tepals and creamy-yellow anthers. In the spring, the stems show green sprouts.
Clematis viticella is a very toxic plant, even after cooking. Be careful with young sprouts, not to be confused with Clematis vitalba .
All parts of Clematis viticella contain various cardiac glycosides as well as ranunculin, a glucoside which breaks down into the toxin protoanemonin in the digestive system. This toxin can cause neurological and cardiac disturbances .
Clematis viticella, poisonous plant
 Clematis viticella, Natural resources conservation service PLANT Database, USDA, 2016
 Nancy J. Turner, Patrick von Aderkas, The North American guide to common poisonous plants and mushrooms