Birthwort (Aristolochia clematitis) - formerly used as a medicinal plant, though it is poisonous, and is now occasionally found established outside of its native range as a relic of cultivation, particularly near nunnerìes because of its use as an abortificent...hence the common name 'birthwort'. It is thought to be the cause of thousands of kidney failures in Romania, Bulgaria, Serbia, Bosnia and Herzegovina and Croatia due to unintentional consumption through contaminated flour