Xylaria hypoxylon is a species of fungus in the genus Xylaria. It is known by a variety of common names, such as the candlestick fungus, the candlesnuff fungus, carbon antlers, or the stag's horn fungus. The fruit bodies, characterized by erect, elongated black branches with whitened tips, typically grow in clusters on decaying hardwood. The fungus can cause a root rot in hawthorn and gooseberry plants.