Syrups are items that appear in many Mario RPG games. When used, they restore a certain amount of FP (or SP/BP) depending on the type.
Super Mario RPG: Legend of the Seven Stars
Syrups first appear in Super Mario RPG: Legend of the Seven Stars, serving as an item that restores FP. Three types are found in the game; Honey Syrup, which heals 10 FP, Maple Syrup, which heals 40 FP, and Royal Syrup, which maxes out FP.
Syrups appear again in Paper Mario, still, as items that recover FP. Honey Syrup and Maple Syrup return, however, Royal Syrup does not. Jammin' Jelly serves as the replacement for it.