The plant also called false hellebore that contains teratogenic compounds is Veratrum. This genus includes poisonous perennial plants known as false hellebores or corn lilies, and it is unrelated to the true hellebores in the genus Helleborus despite the similar common name.
Veratrum species contain highly toxic steroidal alkaloids, including veratridine and related compounds that disrupt sodium channels. They also contain cyclopamine, a teratogenic steroid associated with holoprosencephaly, a serious developmental defect documented in exposed farm animals. The roots and rhizomes are generally the most dangerous parts.
Ingestion can cause vomiting, abdominal pain, numbness, sweating, weakness, slow heartbeat, low blood pressure, arrhythmias, and seizures. Veratrum has a long history of dangerous confusion with edible wild plants, particularly young shoots of wild onion and ramps. Its historical medicinal use reflects the plant’s potency, not its safety; even small doses can have severe cardiovascular effects.