|"Is this all real? Or has this been happening inside my head?"
The topic of this article is of a real-life subject that has been mentioned "in-universe" in a canon source. The Harry Potter Wiki is written from the perspective that all information presented in canon is true (e.g., Hogwarts really exists), and, as such, details contained in this article may differ from real world facts.
The bulb of the squill is a structure that functions as food storage organs during the dormant state of the plant. Squill bulbs have Potion-making properties and are best harvested just after the plants flower.
Squill are used by Muggles to manufacture cough medicines, while wizards use it as an ingredient for Felix Felicis — renowned Potioneer Zygmunt Budge remarked that it was perhaps the squill that gave Felix Felicis its smooth texture.
- Wonderbook: Book of Potions (First appearance)