Tincture of Queensfoil
From Destinypedia, the Destiny wiki
Tincture of Queensfoil is a potion brewed by the Techeuns that allowed one to see into the Ascendant realm. In its natural state, queensfoil was highly poisonous and had to be prepared carefully into a tincture in order to avoid killing those who drank it. Even when made properly, the visions and prophecies one could see under the tincture's influence could destroy weaker minds.
List of appearances