The Protea is an alchemy item that is used to make the Invisibility Potion, which needs 3 Protea, 1 glass, and a nearby alchemy table. It is obtained by Random Spawning (spawns anywhere, gives 1 Protea per item), and Flower Pots (can spawn randomly here, or be planted here, gives 1 Protea per item).
Game Description: "A grey flower that slightly resembles a big eye."