Muggles' Guide to Harry Potter/Magic/Dittany

Overview
Dittany is a plant that was spoken of in the reference One Thousand Magical Herbs and Fungi. In this passage it is said that many believe dittany to have magical powers.

Extended Description
Dittany is first mentioned in Harry Potter and the Philosopher's Stone; Harry, on his Easter holiday, looking it up as part of his studying. No mention of its properties or uses are made at this time.

Not much mention is made of Dittany until Harry Potter and the Half-Blood Prince. There, when Harry uses the Sectumsempra curse on Malfoy, Professor Snape says that he will use Dittany on Malfoy's closed wounds to avoid scarring.

Dittany is used extensively on wounds in Harry Potter and the Deathly Hallows, starting with the occasion when Ron loses a piece of his arm through being Splinched.

Analysis
Dittany is a real herb; the name refers to two different species, White Dittany Dictamnus albus and Dittany of Crete Origanum dictamnus. Both plants have medicinal value against digestive ills, and White Dittany also secretes an oil which has some anti-inflammatory properties.