Echium vulgare

Echium vulgare, known as viper's bugloss and blueweed, is a species of flowering plant in the borage family Boraginaceae. It is native to most of Europe and western and central Asia and it occurs as an introduced species in north-eastern North America, south-western South America and the South and North Island of New Zealand. If eaten, the plant is toxic to horses and cattle through the accumulation of pyrrolizidine alkaloids in the liver.

The plant root was used in ancient times as a treatment for snake or viper bites. According to the Doctrine of signatures, plants were thought to have traits (in this case a speckled stem reminiscent of snake skin, and flowers like an open viper's mouth) that mirror the ailment they treat.