The Wilted Wolfsbane is one of the ingredients to create the Anti-Vampirism Serum.
How to Get the Wilted Wolfsbane
There’s already a wolfsbane on the beaker on laboratory but it needs some hit to wilt it. On the armory room you should take the canon ball outside to the fireroom. Push it to the fire to make it burning. There’s a small door just before the armory room, place the burning canon ball there and go back to the laboratory. Beside the beaker, look for the lever to the dumbwaiter. It will rise and the hot cannonball will roll out and come to a stop underneath the wolfsbane in the beaker. This will make the wolfsbane wilted and you’ll get the Wilted Wolfsbane.