The Ancient Silver Maple Stakes are stakes forged by Gaia from the Silver Maple Ash Tree. They are the only weapons that can permanently kill a Primordial.
Sometime 4,000 years ago Gaia obtained the blood of the Primordials. Using their blood she created Silver Maple Ash Tree. From the tree she created the stakes so that they can be used to kill them, fearing that they were truly immortal. Before Gaia could used them she was killed by the Primordial werewolf Starrk.
For the stakes to work they most be placed within the heart of the Primordial and then the Primordial's body will burst into blue flames and turn into dust.