It is simple to comprehend why the fungus Xylaria polymorpha could cause alarm in a person. It is often reminiscent of grimy human digits extending out from unknown depths beneath the forest floor, earning it the term “dead man’s fingers.” [Citation needed] [Citation needed] It will occasionally develop a single stem, but more often than not, it will develop two to five branches that are grouped together. Tom Volk, a biology professor at the University of Wisconsin–La Crosse who teaches mycology, states that each “finger” can grow up to eight centimeters tall, even though they are often shorter. Volk teaches the subject of mycology.
X. polymorpha appears to be harmless, at least to human beings, despite the fact that it has a macabre appearance. East of the Rockies Mountains is the most prevalent location for this type of wood-rotting fungus, which can grow either alongside or on top of tree roots as it spreads. (Volk also notes that X. polymorpha seems to be a member of what is known as a “species complex,” which refers to a group of closely related species that are difficult to differentiate from one another.)
In the spring, the fungus first manifests itself as fruiting bodies that are whitish in color and generate conidia, which are asexual spores. After some time, the conidia will flake off, and by autumn, the finger-like bodies will have become rough, brown or black on the outside, while the interior will continue to be white.
In this mature stage, one of the “fingers” will have a series of tiny, black, flask-shaped dots termed perithecia lodged in the outer layer of tissue. These dots can be seen when a cross-section is taken of the finger. A layer of spore-filled sacs known as asci can be seen within each and every perithecium. In order to distribute these sexual spores, each ascus elongates onto the outer tip of the perithecium one at a time until it is exposed to the air, at which point it fires the spores out into the surrounding environment. After then, it begins to shrink, and a subsequent ascus begins to grow closer to the tip.
Thus, that occurrence is required for each and every one of the asci in there. “It has to develop out on its own in order for it to be able to release its spores into the surrounding environment,” Volk explains.
The completion of this process can take some time. Volk writes that whereas most mushrooms only live for a few days and release all of their spores during that time, “it can take several months or even years” for the X. polymorpha to do so. It is a time-release mechanism that ensures that at least some of the spores will be dispersed during a favorable time, which is when conditions are wetter and more conducive to the germination of spores. “This is to the advantage of the fungus; it is a time-release mechanism that ensures that at least some of the spores will be dispersed during a favorable time.”
Volk adds that X. polymorpha is not edible because of its toughness and its texture, which is similar to that of wood. If you happen to be out looking for mushrooms, it’s probably best to just give a quick wave to these fingers as you go by.
