Rowan Staff

The Rowan Staff is a magical staff and a powerful artifact of the Old Religion carved from the Rowan Tree that grows at the very heart of the Isle of the Blessed. Only the High Priestesses and their Blood Guards had ever set eyes on it. It is possible that the red tree on a black banner, Morgana and Morgause's crest when they conquered Camelot, which is also the symbol on the Blood Guards' uniforms, represents the Rowan Tree on the Isle of the Blessed, it also could've represented their father, Gorlois.

Morgause, High Priestess of the Old Religion, gave the Staff to her half-sister Morgana in order to allow her to perform necromancy. Morgana in the beginning was unsure because she thought her magic was too weak to wield such a powerful instrument, but Morgause ensured her that the Staff would guide her, because it carried its own power. During the Great Battle for Camelot, she went to the castle's vaults and drove the Staff into the stone floor, screaming and releasing a blast of energy that only those with magic could feel. As she watched, the staff's power allowed her to perform necromancy, as dozens of skeletal hands burst from the floor of the crypt. Morgana didn't have to chant a spell, because the Staff's power was strong enough and it was the Staff itself to guide her. She awoke Camelot's dead warriors in order to force Camelot's Knights to fight on two fronts and against an immortal army. Anyway, the Staff was destroyed by Merlin, who had defeated Morgana. The young warlock shattered the Rowan Staff in two parts using his sword and a spell ("Snæde!"). This caused another magical blast of energy to be released and the skeleton warriors to collapse into inert piles of bones as the enchantment that kept them alive had been broken (The Tears of Uther Pendragon).