Xylaria polymorpha
Encyclopedia
Xylaria polymorpha, commonly known as dead man's fingers, is a saprobic fungi. 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 colonise substrates like woody legume pods, petiole
Petiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...

s, and herbaceous stems. It is characterized by its elongated upright, clavate, or strap-like stromata poking up through the ground, much like fingers. The genus Xylaria
Xylaria
Xylaria is a genus of ascomycetous fungi commonly found growing on dead wood. The name comes from the Greek xýlon meaning wood .Two of the common species of the genus are Xylaria hypoxylon and Xylaria polymorpha....

 contains about 100 species of cosmopolitan
Cosmopolitan distribution
In biogeography, a taxon is said to have a cosmopolitan distribution if its range extends across all or most of the world in appropriate habitats. For instance, the killer whale has a cosmopolitan distribution, extending over most of the world's oceans. Other examples include humans, the lichen...

 fungi. Polymorpha means “many forms.” As its name suggests, it has a very variable but often club-shaped fruiting body (stroma) resembling burned wood.

Often this fungus is found with a multitude of separate “digits” but at times the individual parts will be fused together.

Belonging to the class of fungus known as Ascomycetes (division Mycota) known as the sac fungi, they are characterized by a saclike structure, the ascus
Ascus
An ascus is the sexual spore-bearing cell produced in ascomycete fungi. On average, asci normally contain eight ascospores, produced by a meiotic cell division followed, in most species, by a mitotic cell division. However, asci in some genera or species can number one , two, four, or multiples...

, which contains anything from four to eight ascospores in the sexual stage. The sac fungi are separated into subgroups based on whether asci arise singly or are borne in one of several types of fruiting structures, or ascocarp
Ascocarp
An ascocarp, or ascoma , is the fruiting body of an ascomycete fungus. It consists of very tightly interwoven hyphae and may contain millions of asci, each of which typically contains eight ascospores...

s, and on the method of discharge of the ascospores. Many ascomycetes are plant pathogens, some are animal pathogens, a few are edible mushrooms, and many live on dead organic matter (as saprobes). The largest and most commonly known ascomycetes include the morel
Morel
Morchella, the true morels, is a genus of edible mushrooms closely related to anatomically simpler cup fungi. These distinctive mushrooms appear honeycomb-like in that the upper portion is composed of a network of ridges with pits between them....

 and the truffle, however the polymorpha is an inedible variety.

The dark fruiting body (often black or brown, but sometimes shades of blue/green) is surprisingly white on the inside, with a blackened dotted area all around. This blackened surrounding area is made up of tiny structures called perithecia. The perithecia hold a layer of asci which contain the ascospore
Ascospore
An ascospore is a spore contained in an ascus or that was produced inside an ascus. This kind of spore is specific to fungi classified as ascomycetes ....

s. The asci elongate into the ostiole
Ostiole
An ostiole is a small hole or opening through which algae or ascomycetal fungi release their mature spores. The term is also used in higher plants, for example to denote the opening of the involuted fig inflorescence through which fig wasps enter to pollinate and breed....

, and discharge the ascospores outward. The spore distribution is a lengthy process, sometimes taking several months to complete this part of the life cycle, this is not a common trait amongst fungi, as is normally a much swifter process.

In springtime this fungus often produces a layer of white or bluish asexual spores called conidia, which grow on its surface and surrounding area.
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