Delphinine
Delphinine is a toxic diterpenoid alkaloid found in plants from the Delphinium (larkspur) and Atragene (a clematis) genera, both in the family Ranunculaceae. Delphinine is the principal alkaloid found in Delphinium staphisagria seeds – at one time, under the name stavesacre, a very well known herbal treatment for body lice. It is related in structure and has similar effects to aconitine, acting as an allosteric modulator of voltage gated sodium channels, and producing low blood pressure, slowed heart rate and abnormal heart rhythms. These effects make it highly poisonous (LD50 1.5–3.0 mg/kg in rabbit and dog; frogs are ~10x more susceptible), but in very small doses it has some uses in herbal medicine.