Delphinium

All parts of these plants are considered toxic to humans, causing severe digestive discomfort if ingested & also skin irritation.

Early reports of drinking small amounts of larkspur helped against the sting of scorpions.

They have been used in the treatment of dropsy & spasmodic asthma, generally in the form of a tincture, which has been much employed as a lotion, or as an ointment for the destruction of lice.

PRECAUTIONS:

Ingestion leads to nausea, vomiting, abdominal pain, muscular spasms.
If fatal, death is usually due to respiratory collapse or cardiac arrest. 

MAGIC:

It is said that if you gaze at the Midsummer fires through a bunch of Delphinium, your eyesight will improve.
In Transylvania it was believed to keep witches away from stables.
Larkspur keeps away ghosts while frightening scorpions & other poisonous creatures.