When it first appears above ground in the spring, the club or finger-shaped fruit of Dead Man’s Fingers (Xylaria polymorpha) appears powdery white from the asexual spores that cover its surface. As it matures, it acquires a crusty, black surface. This is the sexual stage. The interior of the fruiting body of this fungus is white; just inside the outer surface is a blackened, dotted layer containing structures called perithecia which hold sacs of spores.
Dead Man’s Fingers, unlike most fungi, which release their spores in a few hours or days, releases its spores over months, or even years. It can have many separate fingers, sometimes fused together to resemble a hand. Look for this fungus growing on hardwood stumps and logs, particularly American beech and maples.