Harry Potter's World: Renaissance Science, Magic, and Medicine

Wolfsbane, also known as aconite or monkshood, was used for hundreds of years in Europe and Asia for a variety of purposes, such as fever reduction and for tipping arrows with poison. As the latter example suggests, wolfsbane is highly toxic and not recommended for medical use. In the Harry Potter series, wolfsbane is used in the Wolfsbane Potion, a concoction to alleviate the symptoms of werewolfery.

Sneezewort, also known as ptarmica, arnica, and neesewurt, is used topically to treat pain from sprains and bruises, although there is little supporting evidence for this practice. In the Harry Potter series, it is mentioned as an ingredient in the Befuddlement Draught, which makes people reckless and belligerent.

Traditionally, wormwood has been used to treat parasites, as a digestive aid, and as an ingredient in absinthe. Wormwood is a common potion ingredient in the Harry Potter series, and is used to make the Draught of the Living Death, the Shrinking Solution, and the Elixir to Induce Euphoria.

Because of its limb-like tubers and vaguely human appearance, the mandrake gained an almost mystical reputation during the Renaissance. The "doctrine of signatures," which held that natural substances acted upon the human body depending on their appearance, was a good match for a root that looked (sometimes with some help) like a little person. JK Rowling's description of the mandrake root as a baby with a lethal scream was not so far off the actual legend.

But by the late 18th century, naturalists like William Woodville were having none of it:

The superstitious and absurd stories, formerly told of the Mandrake, would not now for a moment impose upon the most credulous and ignorant: the great resemblance of some of the roots to the human form, the danger of taking them out of the ground, and their surprising effects, were all the invention of charlatanical knavery and imposture.

Nonetheless, Woodville found that a little mandrake root did relieve his gout.