Indeed, it was only natural that our ancestors, from their dread of the serpent on account of its poisonous sting, as well as from their antipathy to it as the symbol of evil, should ascertain those plants which seemed either attractive, or antagonistic, to this much-dreaded reptile.

Accordingly certain plants, from being supposed to be distasteful to serpents, were much used as amulets to drive them away.

Foremost among these may be mentioned the ash, to escape contact with which a serpent, it has been said, would even creep into the fire, in allusion to which Cowley thus writes: "But that which gave more wonder than the rest, Within an ash a serpent built her nest And laid her eggs, when once to come beneath The very shadow of an ash was death." Gerarde notices this curious belief, and tells us that, "the leaves of this tree are so great virtue against serpents that they dare not so much as touch the morning and evening shadows of the tree, but shun them afar off." Hence ash-sap was a German remedy for serpent bites.

Lucan, in his "Pharsalia" (915-921), has enumerated some of the plants burned for the purpose of expelling serpents: "Beyond the farthest tents rich fires they build, That healthy medicinal odours yield, There foreign galbanum dissolving fries, And crackling flames from humble wallwort rise.
There tamarisk, which no green leaf adorns, And there the spicy Syrian costos burns; There centaury supplies the wholesome flame, That from Therssalian Chiron takes its name; The gummy larch tree, and the thapsos there, Woundwort and maidenweed perfume the air, There the long branches of the long-lived hart With southernwood their odours strong impart, The monsters of the land, the serpents fell, Fly far away and shun the hostile smell." The smoke of the juniper was equally repellent to serpents, and the juice of dittany "drives away venomous beasts, and doth astonish them." In olden times, for serpent bites, agrimony, chamomile, and the fruit of the bramble, were held efficacious, and Gerarde recommends the root of the bugloss, "as it keepeth such from being stung as have drunk it before; the leaves and seeds do the same." On the other hand, some plants had the reputation of attracting serpents, one of these being the moneywort or creeping loosestrife, with which they were said to heal themselves when wounded.

As far back as the time of Pliny serpents were supposed to be very fond of fennel, restoring to them their youth by enabling them to cast their old skins.