Xylaria polymorpha, also known as the dead man's fingers or the fungus of the decaying wood, is a type of fungus that grows on decaying wood and resembles the shape of human fingers. This fungus belongs to the genus Xylaria and is characterized by its cylindrical and finger-like appearance. Some of the synonyms for this fungus include Xylaria hypoxylon, Hypoxylon fragiforme, and Xylaria fusca. However, despite having different names, they all refer to the same fungus. This species of fungi can be found worldwide and has been extensively studied for its medicinal properties and ecological significance.