Xylaria polymorpha, commonly known as dead man’s fingers, is a saprobic fungus. It is a common inhabitant of forest and woodland areas, usually growing from the bases of rotting or injured tree stumps and decaying wood. It has also been known to colonize substrates like woody legume pods, petioles, and herbaceous stems. It is characterized by its elongated upright, clavate, or strap-like stromata poking up through the ground, much like fingers.
info via WIKIPEDIA