"...some species of squill are used in Muggle cough remedies. Perhaps it is this ingredient that gives Felix Felicis a distinctive smoothness. Those who have tasted it rarely forget it."
-- Zygmunt Budge (BoP)
Squill is a mundane flower whose a bulb is used as a potion ingredient.
- Squill belong to the family Asparagacaeae and have brightly-colored flowers. The bulbs are harvested just after they flower, and are used in Muggle cough medicines as well as magical Felix Felicis, or liquid luck (BoP).