Meripilus giganteus
Encyclopedia
Meripilus giganteus is a polypore
fungus
in the Meripilaceae
family. It causes a white rot in various types of broadleaved trees, particularly beech
(Fagus), but also Abies, Picea, Pinus, Quercus and Ulmus species. This bracket fungus, commonly known as the giant polypore or black-staining polypore, is often found in large clumps at the base of trees, although fruiting bodies are sometimes found some distance away from the trunk, parasitizing the roots. M. giganteus has a circumboreal distribution in the northern Hemisphere
, and is widely distributed in Europe. In the field, it is recognizable by the large, multi-capped fruiting body, as well as its pore surface that quickly darkens black when bruised or injured.
s consist of numerous rosette
-like flattened fan-shaped pilei
; they are typically 50 – in diameter and 20 – high. The individual caps, up to 20–80 cm (7.9–31.5 in) diameter and 1 – thick, arise from a common basal stem.
The color of the cap surface is pale tan to dull chestnut brown in young specimens but darkens in age to become concentric zones (zonate) of various shades of brown.
The surface is also finely fibrillose with tiny scales (squamules). There are 3 to 6 pores per millimeter on the underside; the pore surface bruises brown and black, helping to distinguish it from the similar species Grifola frondosa
.
Microscopic features
Spore
s are roughly spherical to ovoid or ellipsoid in shape, with typical dimensions of 6–6.5 × 5.5–6 µm
. Under a microscope, they appear translucent (hyaline
), smooth, and nonamyloid
, meaning that they do not absorb stain from Melzer's Reagant. The basidia—the spore-bearing cells—are club-shaped, 4-spored, and are 22–40 by 7–8 µm.
Polypore fungi may be further distinguished by the type of hyphae that makes up their fruiting body. M. giganteus has a so-called monomitic hyphal system, as its fruiting body is composed of only vegetative hyphae.
).
, Alnus, Betula, Castanea, Celtis, Corylus, Eucalyptus
, Laurus
, Myrica
, Persea
, Pittosporum
, Platanus
, Populus, Prunus
, Pyrus, Tilia
, Ulmus; it has also been found growing on the coniferous species Abies, Larix, and Pinus.
M. giganteus is has a circumboreal distribution in the northern hemisphere. It has been collected from Europe
, Scandinavia
, the area formerly known as the USSR, Iran
and Turkey
. Although many field guides list it as occurring in North America, this is due to confusion with the related M. sumstinei; M. giganteus is not found in North America
. A study of the frequency of occurrence of wood-decay fungi
on street trees and park trees in Hamburg
, Germany found that M. giganteus was the most common species.
extract
from this mushroom has been shown contains compounds that are significantly cytotoxic to the mouse cancer
cell line 3LL.
is similar in overall appearance, but may be distinguished by its more greyish cap, and larger pores.
Polypore
Polypores are a group of tough, leathery poroid mushrooms similar to boletes, but typically lacking a distinct stalk. The technical distinction between the two types of mushrooms is that polypores do not have the spore-bearing tissue continuous along the entire underside of the mushroom. Many...
fungus
Fungus
A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...
in the Meripilaceae
Meripilaceae
The Meripilaceae are a family of fungi in the order Polyporales.-Genera:*Grifola*Henningsia*Hydnopolyporus*Meripilus*Physisporinus*Rigidoporus...
family. It causes a white rot in various types of broadleaved trees, particularly beech
Beech
Beech is a genus of ten species of deciduous trees in the family Fagaceae, native to temperate Europe, Asia and North America.-Habit:...
(Fagus), but also Abies, Picea, Pinus, Quercus and Ulmus species. This bracket fungus, commonly known as the giant polypore or black-staining polypore, is often found in large clumps at the base of trees, although fruiting bodies are sometimes found some distance away from the trunk, parasitizing the roots. M. giganteus has a circumboreal distribution in the northern Hemisphere
Northern Hemisphere
The Northern Hemisphere is the half of a planet that is north of its equator—the word hemisphere literally means “half sphere”. It is also that half of the celestial sphere north of the celestial equator...
, and is widely distributed in Europe. In the field, it is recognizable by the large, multi-capped fruiting body, as well as its pore surface that quickly darkens black when bruised or injured.
Description
The basidiocarpBasidiocarp
In fungi, a basidiocarp, basidiome or basidioma , is the sporocarp of a basidiomycete, the multicellular structure on which the spore-producing hymenium is borne. Basidiocarps are characteristic of the hymenomycetes; rusts and smuts do not produce such structures...
s consist of numerous rosette
Rosette
-People:* Rosette , a French actress* Rosette Bir , a French sculptor* Clinton Rosette , a prominent citizen of DeKalb, Illinois...
-like flattened fan-shaped pilei
Pileus (mycology)
The pileus is the technical name for the cap, or cap-like part, of a basidiocarp or ascocarp that supports a spore-bearing surface, the hymenium. The hymenium may consist of lamellae, tubes, or teeth, on the underside of the pileus...
; they are typically 50 – in diameter and 20 – high. The individual caps, up to 20–80 cm (7.9–31.5 in) diameter and 1 – thick, arise from a common basal stem.
The surface is also finely fibrillose with tiny scales (squamules). There are 3 to 6 pores per millimeter on the underside; the pore surface bruises brown and black, helping to distinguish it from the similar species Grifola frondosa
Grifola frondosa
Grifola frondosa is a polypore mushroom that grows in clusters at the base of trees, particularly oaks. The mushroom is commonly known among English speakers as Hen-of-the-Woods, Ram's Head and Sheep's Head...
.
Microscopic features
Spore
Spore
In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa. According to scientist Dr...
s are roughly spherical to ovoid or ellipsoid in shape, with typical dimensions of 6–6.5 × 5.5–6 µm
Micrometre
A micrometer , is by definition 1×10-6 of a meter .In plain English, it means one-millionth of a meter . Its unit symbol in the International System of Units is μm...
. Under a microscope, they appear translucent (hyaline
Hyaline
The term hyaline denotes a substance with a glass-like appearance.-Histopathology:In histopathological medical usage, a hyaline substance appears glassy and pink after being stained with haematoxylin and eosin — usually it is an acellular, proteinaceous material...
), smooth, and nonamyloid
Amyloid (mycology)
In mycology the term amyloid refers to a crude chemical test using iodine in either Melzer's reagent or Lugol's solution, to produce a black to blue-black positive reaction. It is called amyloid because starch gives a similar reaction, and that reaction for starch is also called an amyloid reaction...
, meaning that they do not absorb stain from Melzer's Reagant. The basidia—the spore-bearing cells—are club-shaped, 4-spored, and are 22–40 by 7–8 µm.
Polypore fungi may be further distinguished by the type of hyphae that makes up their fruiting body. M. giganteus has a so-called monomitic hyphal system, as its fruiting body is composed of only vegetative hyphae.
Edibility
The giant polypore is generally considered inedible, due to its very coarse flesh and mildly acidic taste, although younger specimens may be more palatable; one author notes that it is "eaten in Japan." Also, it may be mistakenly consumed because of its resemblance with the edible species commonly known as Hen of the Woods (Grifola frondosaGrifola frondosa
Grifola frondosa is a polypore mushroom that grows in clusters at the base of trees, particularly oaks. The mushroom is commonly known among English speakers as Hen-of-the-Woods, Ram's Head and Sheep's Head...
).
Habitat and distribution
This mushroom can be found growing of hardwoods, more rarely on conifers. According to Ryvarden and Gilbertson in their monograph on the polypores of Europe, M. giganteus grows especially on Quercus and Fagus tree species, but it has also been collected on the hardwoods Acer, AesculusAesculus
The genus Aesculus comprises 13-19 species of woody trees and shrubs native to the temperate northern hemisphere, with 6 species native to North America and 7-13 species native to Eurasia; there are also several hybrids. Species are deciduous or evergreen...
, Alnus, Betula, Castanea, Celtis, Corylus, Eucalyptus
Eucalyptus
Eucalyptus is a diverse genus of flowering trees in the myrtle family, Myrtaceae. Members of the genus dominate the tree flora of Australia...
, Laurus
Laurus
-Overview:Laurus is a genus of evergreen trees belonging to the Laurel family, Lauraceae. The genus includes three species, whose diagnostic key characters often overlap ....
, Myrica
Myrica
Myrica is a genus of about 35–50 species of small trees and shrubs in the family Myricaceae, order Fagales. The genus has a wide distribution, including Africa, Asia, Europe, North America and South America, and missing only from Australasia...
, Persea
Persea
Persea is a genus of about 150 species of evergreen trees belonging to the laurel family, Lauraceae. The best-known member of the genus is the avocado, P. americana, widely cultivated in subtropical regions for its large, edible fruit.-Overview:...
, Pittosporum
Pittosporum
Pittosporum is a genus of about 200 species of flowering plants in the family Pittosporaceae. The genus is probably Gondwanan in origin; its present range extends from Australasia, Oceania, eastern Asia and some parts of Africa. Citriobatus is usually included here, but might be a distinct genus...
, Platanus
Platanus
Platanus is a small genus of trees native to the Northern Hemisphere. They are the sole living members of the family Platanaceae....
, Populus, Prunus
Prunus
Prunus is a genus of trees and shrubs, which includes the plums, cherries, peaches, apricots and almonds. There are around 430 species spread throughout the northern temperate regions of the globe. Many members of the genus are widely cultivated for fruit and ornament.-Botany:Members of the genus...
, Pyrus, Tilia
Tilia
Tilia is a genus of about 30 species of trees native throughout most of the temperate Northern Hemisphere. The greatest species diversity is found in Asia, and the genus also occurs in Europe and eastern North America, but not western North America...
, Ulmus; it has also been found growing on the coniferous species Abies, Larix, and Pinus.
M. giganteus is has a circumboreal distribution in the northern hemisphere. It has been collected from Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, Scandinavia
Scandinavia
Scandinavia is a cultural, historical and ethno-linguistic region in northern Europe that includes the three kingdoms of Denmark, Norway and Sweden, characterized by their common ethno-cultural heritage and language. Modern Norway and Sweden proper are situated on the Scandinavian Peninsula,...
, the area formerly known as the USSR, Iran
Iran
Iran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia...
and Turkey
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...
. Although many field guides list it as occurring in North America, this is due to confusion with the related M. sumstinei; M. giganteus is not found in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
. A study of the frequency of occurrence of wood-decay fungi
Wood-decay fungus
A wood-decay fungus is a variety of fungus that digests moist wood, causing it to rot. Some wood-decay fungi attack dead wood, such as brown rot, and some, such as Armillaria , are parasitic and colonize living trees. Fungi that not only grow on wood but actually cause it to decay, are called...
on street trees and park trees in Hamburg
Hamburg
-History:The first historic name for the city was, according to Claudius Ptolemy's reports, Treva.But the city takes its modern name, Hamburg, from the first permanent building on the site, a castle whose construction was ordered by the Emperor Charlemagne in AD 808...
, Germany found that M. giganteus was the most common species.
Medicinal properties
The methanolMethanol
Methanol, also known as methyl alcohol, wood alcohol, wood naphtha or wood spirits, is a chemical with the formula CH3OH . It is the simplest alcohol, and is a light, volatile, colorless, flammable liquid with a distinctive odor very similar to, but slightly sweeter than, ethanol...
extract
Extract
An extract is a substance made by extracting a part of a raw material, often by using a solvent such as ethanol or water. Extracts may be sold as tinctures or in powder form....
from this mushroom has been shown contains compounds that are significantly cytotoxic to the mouse cancer
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
cell line 3LL.
Similar species
The polypore fungus Grifola frondosaGrifola frondosa
Grifola frondosa is a polypore mushroom that grows in clusters at the base of trees, particularly oaks. The mushroom is commonly known among English speakers as Hen-of-the-Woods, Ram's Head and Sheep's Head...
is similar in overall appearance, but may be distinguished by its more greyish cap, and larger pores.