ribosome-inactivating lectin called viscumin. symptoms may include acute gastrointestinal discomfort, diarrhea, weak pulse and/or slow heart rate, and even seizures; it is rarely lethal to adult humans, however, and many wild animals are adapted to eating its fruit. voacanga africana the bark and seeds of this tropical tree contain a complex mixture of iboga alkaloids, including voacangine and voacamine. these compounds have been variously used as stimulants, psychedelic drugs, and poisons. wisteria sinensis also known as chinese wisteria. all parts of the plant contain a glycoside called wisterin which is toxic if ingested and may cause nausea, vomiting, stomach pains, and diarrhea. wisterias have caused poisoning in children of many countries, producing mild to severe gastroenteritis. xanthium spp. several species commonly known as cocklebur. the common cocklebur (xanthium strumarium), a native of north america, can be poisonous to livestock, including horses, cattle, and sheep. some domestic animals will avoid consuming the plant if other forage is present, but less discriminating animals, such as pigs, will consume the plants and then sicken and die. the seedlings and seeds are the most toxic parts of the plants. symptoms usually occur within a few hours, producing unsteadiness and weakness, depression, nausea and vomiting, twisting of the neck muscles, rapid and weak pulse, difficulty breathing, and eventually death. xanthium has also been used for its medicinal properties and for making yellow dye, as indicated by its name (greek xanthos = 'yellow'). zantedeschia aethiopica known as calla lily or arum lily. all parts of the plant are toxic, containing calcium oxalate, which induces irritation and swelling of the mouth and throat, acute vomiting and diarrhea. can be fatal. zigadenus glaberrimus commonly known as death camas. all parts of z. glaberrimus are toxic, due to the presence of alkaloids. this or related species have caused human fatalities.