Luminescent Panellus

The fungus normally exists unseen, in the form of a mass of threadlike vegetative cells called a mycelium, inhabiting rotting wood; only when suitable environmental conditions of temperature, moisture, and nutrient availability are achieved does the fungus produce the reproductive structures known as fruit bodies, or mushrooms. The cap of the fruit body is kidney- or clamshell-shaped, convex to roughly flat, with dimensions of 1.2 to 3.2 cm (0.5 to 1.3 in) by 1.2 to 2.5 cm (0.5 to 1.0 in). The edges of the caps are scalloped with small rounded teeth, and curved slightly inward. The cap surface is dry, with a pattern of block-like areas similar to cracked dried mud; the surface is also covered with small fine hairs that give it a somewhat woolly consistency. It may have several concentric ridges or zones. Fresh fruit bodies range in color from yellowish-orange to buff to cinnamon; when dried they may be various shades of tan, brown or clay. The faded colors of dried fruit bodies tend to revive when moistened. On the underside of the cap, the gills are narrow and spaced closely together, often forked, brownish to buff, and with numerous interconnecting cross-veins. Supporting the cap is a stem that is 0.5 to 2 cm (0.2 to 0.8 in) long by 0.3 to 0.8 cm (0.1 to 0.3 in) thick and has an off-center attachment to the cap, either at or near the cap side. …

Panellus stipticus is common in northern temperate regions of Europe, and has also been collected in Australia, New Zealand, Anatolia, Japan, and China. In North America, it is more common in the east than the west; the mushroom's northern range extends to Alaska, and it has been collected as far south as Costa Rica. Panellus stipticus is a saprobic species, and causes a white rot. This is a form of wood decay in which the wood assumes a bleached appearance and where lignin as well as cellulose and hemicellulose is broken down by enzymes secreted by the fungus. Fruit bodies are usually found in tightly overlapping clusters on the sides of hardwood trees, on logs, stumps, and fallen branches. Although most commonly found on dead wood, it can also grow opportunistically in the wounds of living trees. In North America, its preferred hosts are oak, birch, maple, hickory, pecan, and American hornbeam, while in Europe, it is commonly found growing on oak, birch, alder, beech, hazel, chestnut, and ash. It has also been found growing on Ericia in North Africa. Although the fungus favors hardwoods, it has been reported to grow on loblolly pine and eastern white pine. Fruiting occurs September through November in Europe, the Canary Islands, and North America, although it may also sometimes be found in the spring. The fruit bodies are long-lasting and may be found year-round. …

Panellus stipticus is considered too small and bitter to be edible, but is considered nonpoisonous. Its taste has been described as acidic, acrid, or astringent. One 1992 study reported that the taste of the fruit bodies varies across the geographic range of the species. Those from eastern North America have a mildly acrid taste that takes time to develop, and cause uncomfortable drying in the mouth. In contrast, specimens from Japan, New Zealand, and Russia produce no sensation in the mouth, but cause significant constriction and a nauseating taste in the throat. The fruit bodies are reputed to have been used in traditional Chinese medicine as a styptic to staunch bleeding, and also as a "violent purgative".

Bioremediation. As a white-rot fungus, P. stipticus contains enzymes that are able to break down lignin, a complex aromatic polymer in wood that is highly resistant to degradation by conventional enzyme systems. The major enzyme that initiates the cleavage of hydrocarbon rings is laccase, which catalyzes the addition of a hydroxyl group to phenolic compounds (polyphenols). The ring can then be opened between the two adjacent carbon atoms that bear the hydroxyl groups. White-rot fungi are being investigated scientifically for their potential use in the bioremediation of land contaminated by organic pollutants, and to convert industrial wastes rich in toxic polyphenols. …