"Oh, it's a Gurdyroot ... You can keep it if you like, I've got a few of them. They're really excellent for warding off Gulping Plimpies."
-- Luna Lovegood to Ron Weasley (HBP20)
Resembles a green onion.
- According to Luna is excellent for warding off Gulping Plimpies (HBP20).
- Ron wondered if Luna and her father had given a "lifetime supply of Gurdyroots" to Bill and Fleur as a wedding present (DH8)
- It can be made into a drink ("infusion of Gurdyroots") which is deep purple in color and unpleasant to drink to many (DH20).
- When Hermione drank the Polyjuice Potion containing essence of Bellatrix Lestrange, it tasted "disgusting, worse than Gurdyroots" (DH26)
- Mentioned in the radio program Toots, Shoots 'n' Roots ("... tune in next time when we'll be discussing the right way to skin a Gurdyroot ...") (JKR).
- Neville Longbottom once bought a "large, evil-smelling green onion" for magical protection against the creature petrifying people when the Chamber of Secrets was reopened (CS11). The description sounds quite similar to a gurdyroot. And who knows? If it can protect against Gulping Plimpies, it might also be a good Basilisk repellent. Either way, Neville had nothing to fear at that time, since he was a Pureblood and Tom Riddle told his "pet" to attack Muggleborns.
One Muggle plant that resembles the Gurdyroot is the Leek, an ancient vegetable pictured in Egyptian paintings. It is one of the national symbols of Wales, and pictured on the cap badge of the Welsh guards, as well as on the 1985 and 1990 British pound coin.
In his play "Henry the Fifth," Shakespeare mentioned the wearing of the leek symbol to honor both Wales and St. David, who only ate leeks when he fasted and prayed.