- "These are the Wrackspurt siphons — to remove all sources of distraction from the thinker's immediate area. Here, a billywig propeller, to induce an elevated frame of mind. Finally, the dirigible Plum, so as to enhance the ability to accept the extraordinary."
- — Xenophilius Lovegood explains the elements of his replica of Rowena Ravenclaw's Diadem.[src]
The Holiday Blancmange Severus Snape recalled enjoying in his youth used Dirigible plums as ingredients. Snape also told Jacob's sibling that it was supposed to be good for one's health in small doses, as learned from Potions class.
Some, like Xenophilius Lovegood, believed dirigible plums enhanced the ability of one to accept the extraordinary. As such, on his stone bust of Rowena Ravenclaw, and in an attempt to recreate her lost diadem, he included this plant as part of the headdress. His daughter, Luna Lovegood, usually wore a pair of dirigible plums as earrings.
"Dirigible" means "able to be guided"; it is most commonly used in conjunction with airships, which have large motors to push them in the desired direction, instead of drifting before the wind as an unpowered balloon must. The word "dirigible" in the name of these plums could refer to their being shaped like airships, or to their guiding the thoughts of the wearer.
If the dirigible plums do in fact have the ability to enhance one's awareness, as the Lovegood family believes, then they could perhaps be considered akin to the knowledge-increasing "forbidden fruit" (commonly depicted as an apple) given to Eve in the Bible. Xenophilius Lovegood has a sign in front of his house telling visitors to stay away from the plums, which could perhaps be evidence of a symbolic connection between the two — or even an implication that the plums are the original "forbidden fruit" depicted in the Bible.
- Harry Potter and the Order of the Phoenix (First appearance)
- Harry Potter and the Order of the Phoenix (film)
- Harry Potter and the Half-Blood Prince (Mentioned only)
- Harry Potter and the Deathly Hallows (First identified as Dirigible plum)
- Harry Potter and the Deathly Hallows: Part 1
- LEGO Harry Potter: Years 5-7
- Harry Potter: The Character Vault
- Harry Potter: The Creature Vault
- Harry Potter: Wizards Unite
- Harry Potter: Hogwarts Mystery