Dittany

Dittany is a herb with powerful healing properties. Harry Potter looks it up in One Thousand Magical Herbs and Fungi in his first year while studying for his finals (PS14). When Harry injures Draco Malfoy with Sectumsempra, Severus Snape takes Malfoy to the hospital wing, planning to use dittany to prevent scarring (HBP24). Hermione Granger carries Essence of Dittany in her beaded bag when the Trio is on their Horcrux quest (DH14, DH17, DH27).