Hydnellum peckii
Encyclopedia
Hydnellum peckii is an inedible fungus
, and a member of the genus Hydnellum
of the family Bankeraceae
. It is a hydnoid
species, producing spore
s on the surface of vertical spines or tooth-like projections that hang from the undersurface of the fruit bodies
. It is found in North America, Europe, and was recently discovered in Iran (2008) and Korea (2010). Hydnellum peckii is a mycorrhizal species, and forms mutually beneficial relationships with a variety of coniferous trees, growing on the ground singly, scattered, or in fused masses.
The fruit bodies typically have a funnel-shaped cap
with a white edge, although the shape can be highly variable. Young, moist fruit bodies can "bleed" a bright red juice that contains a pigment
known to have anticoagulant
properties similar to heparin
. The unusual appearance of the young fruit bodies has earned the species several descriptive common name
s, including strawberries and cream, the bleeding Hydnellum, the bleeding tooth fungus, the red-juice tooth, and the Devil's tooth. Although Hydnellum peckii fruit bodies are readily identifiable when young, they become brown and nondescript when they age.
by American mycologist Howard James Banker
in 1913. Italian Pier Andrea Saccardo
placed the species in the genus Hydnum
in 1925, while Walter Henry Snell and Esther Amelia Dick placed it in Calodon in 1956; Hydnum peckii (Banker) Sacc. and Calodon peckii Snell & E.A. Dick are synonyms of Hydnellum peckii.
The fungus is classified in the stirps (species thought to be descendants of a common ancestor) Diabolum of the genus Hydnellum, a grouping of similar species with the following shared characteristics: flesh
that is marked with concentric lines that form alternating pale and darker zones (zonate); an extremely peppery taste; a sweetish odor; spores that are ellipsoid, and not amyloid
(that is, not absorbing iodine
when stained
with Melzer's reagent
), acyanophilous (not staining with the reagent Cotton Blue
), and covered with tubercules; the presence of clamp connection
s in the hypha
e. Molecular analysis based on the sequences of the internal transcribed spacer
DNA of several Hydnellum species placed H. peckii as most closely related to H. ferrugineum
and H. spongiosipes.
The specific epithet honors mycologist Charles Horton Peck
. The fungus is known in the vernacular
by several names, including "strawberries and cream", the "bleeding Hydnellum", the "red-juice tooth", "Peck's hydnum", the "bleeding tooth fungus", and the "devil's tooth".
are the reproductive structures that are produced from fungal mycelium
when the appropriate environmental conditions of temperature, humidity and nutrient availability are met. Hydnellum peckii is a stipitate hydnoid fungus, meaning that it has a cap
atop a stipe
(stem), and a form resembling a Hydnum
—characterized by a teeth-like hymenium
, rather than gills or pores on the underside of the cap. Fruit bodies growing closely together often appear to fuse together (this is called "confluence"). They can reach a height of up to 10.5 cm (4.1 in). Fresh fruit bodies exude a striking, thick red juice when they are moist.
The cap's surface is convex to flattened, more or less uneven and sometimes slightly depressed in the center. It is usually densely covered with "hairs" that give it a texture similar to felt or velvet; these hairs are sloughed off in age, leaving the caps of mature specimens smooth. Its shape varies from somewhat round to irregular, 4 to 10 cm (1.6 to 3.9 in), or even as much as 20 cm (7.9 in) wide as a result of confluence. The cap is initially whitish, but later turns slightly brownish, with irregular dark-brown to nearly black blotches where it is bruised. In maturity, the surface is fibrous and tough, scaly and jagged, grayish-brown in the upper part of the cap, and somewhat woody. The flesh
is a pale pinkish-brown.
The teeth are slender, cylindrical and tapering (terete), less than 5 mm (0.196850393700787 in) long, and become shorter closer to the cap edge. They are crowded together, with typically between three and five teeth per square millimeter. Pinkish-white initially, they age to a grayish-brown. The stem is thick, very short, and often deformed. It becomes bulbous where it penetrates the ground, and may root into the soil for several centimeters. Although it may reach up to 5 cm (2 in) in total length, and is 1 to 3 cm (0.393700787401575 to 1.2 in) wide, only about 0.1 to 1 cm (0.0393700787401575 to 0.393700787401575 in) appear above ground. The upper part is covered with the same teeth found on the underside of the cap, whereas the lower part is hairy and often encases debris from the forest floor. The odor of the fruit body has been described as "mild to disagreeable", or, as Banker suggested in his original description, similar to hickory
nuts.
, the spores
appear brown. Viewing them with a light microscope reveals finer details of their structure: they are roughly spherical but end abruptly in a small point, their surfaces are covered with small, wart-like nodules, and their size is between 5.0–5.3 by 4.0–4.7 µm
. The spores are in amyloid
, meaning they do not absorb iodine
when stained
with Melzer's reagent
.
Hydnellum peckiis cells (the hypha
e) also present various characters useful for its characterization. The hyphae that form the cap are hyaline
(translucent), smooth, thin-walled, and 3–4 µm thick. They collapse when dry, but may be readily revived with a weak (2%) solution of potassium hydroxide
. Those in the cap form an intricate tangle with a tendency to run longitudinally. They are divided into cellular compartments (septa
) and have clamp connection
s—short branches connecting one cell to the previous cell to allow passage of the products of nuclear division. The basidia, the spore-bearing cells in the hymenium, are club-shaped, four-spored, and measure 35–40 by 4.7–6 µm.
. The related species H. pineticola also exudes pink droplets of liquid when young and moist. Commonly found growing under conifers in northeastern North America, H. pineticola tastes "unpleasant", but not acrid. Fruit bodies tend to grow singly, rather than in fused clusters, and, unlike H. peckii, they do not have bulbous stems.
l fungus, and as such establishes a mutualistic relationship with the roots of certain trees (referred to as "hosts"), in which the fungus exchanges mineral
s and amino acids extracted from the soil for fixed carbon
from the host. The subterranean hyphae of the fungus grow a sheath of tissue around the rootlets of a broad range of tree species, in an intimate association that is especially beneficial to the host (termed ectomycorrhizal), as the fungus produces enzyme
s that mineralize
organic compounds and facilitate the transfer of nutrients to the tree.
The ectomycorrhizal structures of H. peckii are among a few in the Bankeraceae
that have been studied in detail. They are characterized by a plectenchymatous mantle—a layer of tissue made of hyphae tightly arranged in a parallel orientation, or palisade, and which rarely branch or overlap each other. These hyphae, along with adhering mineral soil particles, are embedded in a gelatinous matrix. The hyphae of the ectomycorrhizae can become chlamydospore
s, an adaptation that helps the fungus tolerate unfavorable conditions. Chlamydospores of H. peckii have a peculiar structure—markedly distinct from those of other Bankeraceae—with thick, smooth inner walls and an outer wall that is split radially into warts. The most striking characteristic of the ectomycorrhizae as a whole is the way the black outer layers of older sections are shed, giving a "carbonized appearance". The majority of the underground biomass of the fungus is concentrated near the surface, most likely as "mycelial mats"—dense clusters of ectomycorrhizae and mycelium. The mycelium is also known to extend far beyond the site of the fruit bodies, as far as 337 centimetres (11.1 ft) away.
Molecular techniques have been developed to help with conservation efforts of stipitate hydnoid fungi, including H. peckii. While the distribution of the fungus has traditionally been determined by counting the fruit bodies, this method has a major drawback in that fruit bodies are not produced consistently every year, and the absence of fruit bodies is not an indication of the absence of its mycelium in the soil. More modern techniques using the polymerase chain reaction
to assess the presence of the fungal DNA
in the soil have helped alleviate the issues in monitoring the presence and distribution of fungi mycelia.
, typically begins associating with more mature hosts once the canopy has closed. A preference for mountainous
or subalpine
ecosystems has been noted.
The fungus has a wide distribution in North America, and is particularly common in the Pacific Northwest
; its range extends north to Alaska
and east to North Carolina
. In the Puget Sound
area of the U.S. state of Washington, it is found in association with Douglas-fir
, fir
, and hemlock
. Along the Oregon Coast
it has been collected under lodgepole pine
. In addition to North America, the mushroom is widespread in Europe, and its presence has been documented in Italy, Germany, and Scotland. The species is common in the latter location, but becoming increasingly rare in several European countries, such as Norway, The Netherlands, and the Czech Republic. Increased pollution in central Europe has been suggested as one possible factor in the mushroom's decline there. Reports from Iran in 2008 and Korea in 2010 were the first outside Europe and North America.
, they are inedible due to their extremely bitter taste. This acridity persists even in dried specimens.
The fruit bodies of this and other Hydnellum species are prized by mushroom dye
rs. The colors may range from beige when no mordant
is used, to various shades of blue or green depending on the mordant added.
, named atromentin (2,5-dihydroxy-3,6-bis(4-hydroxyphenyl
)-1,4-benzoquinone
), and similar in biological activity
to the well-known anticoagulant heparin
. Atromentin also possesses antibacterial activity, inhibiting the enzyme enoyl-acyl carrier protein reductase
(essential for the biosynthesis of fatty acid
s) in the bacteria Streptococcus pneumoniae
.
Hydnellum peckii can bioaccumulate
the heavy metal caesium
. In one Swedish field study, as much as 9% of the total caesium of the topmost 10 cm (3.9 in) of soil was found in the fungal mycelium. In general, ectomycorrhizal fungi, which grow most prolifically in the upper organic horizons of the soil or at the interface between the organic and mineral layers, are involved in the retention and cycling of caesium-137
in organic-rich forest soils.
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...
, and a member of the genus Hydnellum
Hydnellum
Hydnellum is a genus of tooth fungus of the family Bankeraceae in the order Thelephorales. The genus is widely distributed, and contains 38 species. The fruit bodies of its members grow by slowly enveloping bits of grass and vegetation around them. They are too tough and woody to eat comfortably...
of the family Bankeraceae
Bankeraceae
The Bankeraceae are a family of fungi in the order Boletales. Taxa are terrestrial, and ectomycorrhizal with species such as Pinaceae or Fagaceae.-External links:*...
. It is a hydnoid
Hydnoid fungi
The hydnoid fungi are a group of fungi in the Basidiomycota with basidiocarps producing spores on pendant, tooth-like or spine-like projections. They are colloquially called tooth fungi...
species, producing 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 on the surface of vertical spines or tooth-like projections that hang from the undersurface of the fruit bodies
Basidiocarp
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...
. It is found in North America, Europe, and was recently discovered in Iran (2008) and Korea (2010). Hydnellum peckii is a mycorrhizal species, and forms mutually beneficial relationships with a variety of coniferous trees, growing on the ground singly, scattered, or in fused masses.
The fruit bodies typically have a funnel-shaped cap
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...
with a white edge, although the shape can be highly variable. Young, moist fruit bodies can "bleed" a bright red juice that contains a pigment
Pigment
A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, in which a material emits light.Many materials selectively absorb...
known to have anticoagulant
Anticoagulant
An anticoagulant is a substance that prevents coagulation of blood. A group of pharmaceuticals called anticoagulants can be used in vivo as a medication for thrombotic disorders. Some anticoagulants are used in medical equipment, such as test tubes, blood transfusion bags, and renal dialysis...
properties similar to heparin
Heparin
Heparin , also known as unfractionated heparin, a highly sulfated glycosaminoglycan, is widely used as an injectable anticoagulant, and has the highest negative charge density of any known biological molecule...
. The unusual appearance of the young fruit bodies has earned the species several descriptive common name
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...
s, including strawberries and cream, the bleeding Hydnellum, the bleeding tooth fungus, the red-juice tooth, and the Devil's tooth. Although Hydnellum peckii fruit bodies are readily identifiable when young, they become brown and nondescript when they age.
Taxonomy, phylogeny, and naming
The species was first described scientificallySpecies description
A species description or type description is a formal description of a newly discovered species, usually in the form of a scientific paper. Its purpose is to give a clear description of a new species of organism and explain how it differs from species which have been described previously, or are...
by American mycologist Howard James Banker
Howard James Banker
Howard James Banker was an American mycologist. He received his PhD from Columbia University in 1908. Banker was an associate editor of the journal Mycologia starting from its establishment in 1909, until it became the official publication of the Mycological Society of America in 1933...
in 1913. Italian Pier Andrea Saccardo
Pier Andrea Saccardo
Pier Andrea Saccardo was an Italian botanist and mycologist.- Life :...
placed the species in the genus Hydnum
Hydnum
Hydnum is a genus of fungi in the Hydnaceae family. They are notable for their unusual spore-bearing structures of teeth rather than gills. The best known are the edible species Hydnum repandum and H. rufescens. The word is derived from udnon/ύδνον, an Ancient Greek word for truffle...
in 1925, while Walter Henry Snell and Esther Amelia Dick placed it in Calodon in 1956; Hydnum peckii (Banker) Sacc. and Calodon peckii Snell & E.A. Dick are synonyms of Hydnellum peckii.
The fungus is classified in the stirps (species thought to be descendants of a common ancestor) Diabolum of the genus Hydnellum, a grouping of similar species with the following shared characteristics: flesh
Trama (mycology)
In mycology trama is a term for the inner, fleshy portion of a mushroom's basidiocarp, or fruit body. It is distinct from the outer layer of tissue, known as the pileipellis or cuticle, and from the spore-bearing tissue layer known as the hymenium....
that is marked with concentric lines that form alternating pale and darker zones (zonate); an extremely peppery taste; a sweetish odor; spores that are ellipsoid, and not amyloid
Amyloid
Amyloids are insoluble fibrous protein aggregates sharing specific structural traits. Abnormal accumulation of amyloid in organs may lead to amyloidosis, and may play a role in various neurodegenerative diseases.-Definition:...
(that is, not absorbing iodine
Iodine
Iodine is a chemical element with the symbol I and atomic number 53. The name is pronounced , , or . The name is from the , meaning violet or purple, due to the color of elemental iodine vapor....
when stained
Chemical tests in mushroom identification
Chemical tests in mushroom identification are methods that aid in determining the variety of some fungi. The most useful tests are Melzer's reagent and potassium hydroxide.- Ammonia :Household ammonia can be used. A couple of drops are placed on the flesh...
with Melzer's reagent
Melzer's Reagent
Melzer's reagent is a chemical reagent used by mycologists to assist with the identification of fungi.-Composition:...
), acyanophilous (not staining with the reagent Cotton Blue
Methyl blue
Methyl blue, also known as Cotton blue, Helvetia blue, Acid blue 93, or C.I. 42780, is a chemical compound with the molecular formula C37H27N3Na2O9S3. It is used as a stain in histology. Methyl blue stains collagen blue in tissue sections. It is soluble in water and slightly soluble in ethanol...
), and covered with tubercules; the presence of clamp connection
Clamp connection
A clamp connection is a structure formed by growing hyphal cells of certain fungi. It is created to ensure each septum, or segment of hypha separated by crossed walls, receives a set of differing nuclei, which are obtained through mating of hyphae of differing sexual types...
s in the hypha
Hypha
A hypha is a long, branching filamentous structure of a fungus, and also of unrelated Actinobacteria. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium; yeasts are unicellular fungi that do not grow as hyphae.-Structure:A hypha consists of one or...
e. Molecular analysis based on the sequences of the internal transcribed spacer
Internal transcribed spacer
ITS refers to a piece of non-functional RNA situated between structural ribosomal RNAs on a common precursor transcript. Read from 5' to 3', this polycistronic rRNA precursor transcript contains the 5' external transcribed sequence , 18S rRNA, ITS1, 5.8S rRNA, ITS2, 28S rRNA and finally the 3'ETS...
DNA of several Hydnellum species placed H. peckii as most closely related to H. ferrugineum
Hydnellum ferrugineum
Hydnellum ferrugineum is an inedible fungus often found beneath conifers. It was given its current name by German mycologist Petter Karsten in 1879.-External links:*...
and H. spongiosipes.
The specific epithet honors mycologist Charles Horton Peck
Charles Horton Peck
Charles Horton Peck, born March 30, 1833 in Sand Lake, New York, died 1917 in Albany, New York, was an American mycologist of the 19th and early 20th centuries...
. The fungus is known in the vernacular
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...
by several names, including "strawberries and cream", the "bleeding Hydnellum", the "red-juice tooth", "Peck's hydnum", the "bleeding tooth fungus", and the "devil's tooth".
Description
As in all mushroom-producing fungi, the fruit bodies (basidiocarps)Basidiocarp
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...
are the reproductive structures that are produced from fungal mycelium
Mycelium
thumb|right|Fungal myceliaMycelium is the vegetative part of a fungus, consisting of a mass of branching, thread-like hyphae. The mass of hyphae is sometimes called shiro, especially within the fairy ring fungi. Fungal colonies composed of mycelia are found in soil and on or within many other...
when the appropriate environmental conditions of temperature, humidity and nutrient availability are met. Hydnellum peckii is a stipitate hydnoid fungus, meaning that it has a cap
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...
atop a stipe
Stipe (mycology)
thumb|150px|right|Diagram of a [[basidiomycete]] stipe with an [[annulus |annulus]] and [[volva |volva]]In mycology a stipe refers to the stem or stalk-like feature supporting the cap of a mushroom. Like all tissues of the mushroom other than the hymenium, the stipe is composed of sterile hyphal...
(stem), and a form resembling a Hydnum
Hydnum
Hydnum is a genus of fungi in the Hydnaceae family. They are notable for their unusual spore-bearing structures of teeth rather than gills. The best known are the edible species Hydnum repandum and H. rufescens. The word is derived from udnon/ύδνον, an Ancient Greek word for truffle...
—characterized by a teeth-like hymenium
Hymenium
The hymenium is the tissue layer on the hymenophore of a fungal fruiting body where the cells develop into basidia or asci, which produce spores. In some species all of the cells of the hymenium develop into basidia or asci, while in others some cells develop into sterile cells called cystidia or...
, rather than gills or pores on the underside of the cap. Fruit bodies growing closely together often appear to fuse together (this is called "confluence"). They can reach a height of up to 10.5 cm (4.1 in). Fresh fruit bodies exude a striking, thick red juice when they are moist.
The cap's surface is convex to flattened, more or less uneven and sometimes slightly depressed in the center. It is usually densely covered with "hairs" that give it a texture similar to felt or velvet; these hairs are sloughed off in age, leaving the caps of mature specimens smooth. Its shape varies from somewhat round to irregular, 4 to 10 cm (1.6 to 3.9 in), or even as much as 20 cm (7.9 in) wide as a result of confluence. The cap is initially whitish, but later turns slightly brownish, with irregular dark-brown to nearly black blotches where it is bruised. In maturity, the surface is fibrous and tough, scaly and jagged, grayish-brown in the upper part of the cap, and somewhat woody. The flesh
Trama (mycology)
In mycology trama is a term for the inner, fleshy portion of a mushroom's basidiocarp, or fruit body. It is distinct from the outer layer of tissue, known as the pileipellis or cuticle, and from the spore-bearing tissue layer known as the hymenium....
is a pale pinkish-brown.
The teeth are slender, cylindrical and tapering (terete), less than 5 mm (0.196850393700787 in) long, and become shorter closer to the cap edge. They are crowded together, with typically between three and five teeth per square millimeter. Pinkish-white initially, they age to a grayish-brown. The stem is thick, very short, and often deformed. It becomes bulbous where it penetrates the ground, and may root into the soil for several centimeters. Although it may reach up to 5 cm (2 in) in total length, and is 1 to 3 cm (0.393700787401575 to 1.2 in) wide, only about 0.1 to 1 cm (0.0393700787401575 to 0.393700787401575 in) appear above ground. The upper part is covered with the same teeth found on the underside of the cap, whereas the lower part is hairy and often encases debris from the forest floor. The odor of the fruit body has been described as "mild to disagreeable", or, as Banker suggested in his original description, similar to hickory
Hickory
Trees in the genus Carya are commonly known as hickory, derived from the Powhatan language of Virginia. The genus includes 17–19 species of deciduous trees with pinnately compound leaves and big nuts...
nuts.
Microscopic features
In depositSpore print
thumb|300px|right|Making a spore print of the mushroom Volvariella volvacea shown in composite: mushroom cap laid on white and dark paper; cap removed after 24 hours showing pinkish-tan spore print...
, the spores
Basidiospore
A basidiospore is a reproductive spore produced by Basidiomycete fungi. Basidiospores typically each contain one haploid nucleus that is the product of meiosis, and they are produced by specialized fungal cells called basidia. In grills under a cap of one common species in the phylum of...
appear brown. Viewing them with a light microscope reveals finer details of their structure: they are roughly spherical but end abruptly in a small point, their surfaces are covered with small, wart-like nodules, and their size is between 5.0–5.3 by 4.0–4.7 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...
. The spores are in amyloid
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 they do not absorb iodine
Iodine
Iodine is a chemical element with the symbol I and atomic number 53. The name is pronounced , , or . The name is from the , meaning violet or purple, due to the color of elemental iodine vapor....
when stained
Chemical tests in mushroom identification
Chemical tests in mushroom identification are methods that aid in determining the variety of some fungi. The most useful tests are Melzer's reagent and potassium hydroxide.- Ammonia :Household ammonia can be used. A couple of drops are placed on the flesh...
with Melzer's reagent
Melzer's Reagent
Melzer's reagent is a chemical reagent used by mycologists to assist with the identification of fungi.-Composition:...
.
Hydnellum peckiis cells (the hypha
Hypha
A hypha is a long, branching filamentous structure of a fungus, and also of unrelated Actinobacteria. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium; yeasts are unicellular fungi that do not grow as hyphae.-Structure:A hypha consists of one or...
e) also present various characters useful for its characterization. The hyphae that form the cap are 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...
(translucent), smooth, thin-walled, and 3–4 µm thick. They collapse when dry, but may be readily revived with a weak (2%) solution of potassium hydroxide
Potassium hydroxide
Potassium hydroxide is an inorganic compound with the formula KOH, commonly called caustic potash.Along with sodium hydroxide , this colorless solid is a prototypical strong base. It has many industrial and niche applications. Most applications exploit its reactivity toward acids and its corrosive...
. Those in the cap form an intricate tangle with a tendency to run longitudinally. They are divided into cellular compartments (septa
Septum
In anatomy, a septum is a wall, dividing a cavity or structure into smaller ones.-In human anatomy:...
) and have clamp connection
Clamp connection
A clamp connection is a structure formed by growing hyphal cells of certain fungi. It is created to ensure each septum, or segment of hypha separated by crossed walls, receives a set of differing nuclei, which are obtained through mating of hyphae of differing sexual types...
s—short branches connecting one cell to the previous cell to allow passage of the products of nuclear division. The basidia, the spore-bearing cells in the hymenium, are club-shaped, four-spored, and measure 35–40 by 4.7–6 µm.
Similar species
Hydnellum diabolus (the species epithet is given the neuter diabolum in some publications) has a very similar appearance, so much so that some consider it and H. peckii to be synonymous; H. diabolus is said to have a sweetish pungent odor that is lacking in H. peckii. The differences between the two species are amplified in mature specimens: H. diabolus has an irregularly thickened stem, while the stem of H. peckii is thickened by a "definite spongy layer". Additionally, old specimens of H. peckii have a smooth cap, while H. diabolus is tomentoseTomentose
Tomentose is a term used to describe plant hairs that are flattened and matted, forming a woolly coating known as tomentum. Often the hairs are silver or gray-colored...
. The related species H. pineticola also exudes pink droplets of liquid when young and moist. Commonly found growing under conifers in northeastern North America, H. pineticola tastes "unpleasant", but not acrid. Fruit bodies tend to grow singly, rather than in fused clusters, and, unlike H. peckii, they do not have bulbous stems.
Ecology
Hydnellum peckii is a mycorrhizaMycorrhiza
A mycorrhiza is a symbiotic association between a fungus and the roots of a vascular plant....
l fungus, and as such establishes a mutualistic relationship with the roots of certain trees (referred to as "hosts"), in which the fungus exchanges mineral
Mineral
A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...
s and amino acids extracted from the soil for fixed carbon
Carbon fixation
In biology, carbon fixation is the reduction of carbon dioxide to organic compounds by living organisms. The obvious example is photosynthesis. Carbon fixation requires both a source of energy such as sunlight, and an electron donor such as water. All life depends on fixed carbon. Organisms that...
from the host. The subterranean hyphae of the fungus grow a sheath of tissue around the rootlets of a broad range of tree species, in an intimate association that is especially beneficial to the host (termed ectomycorrhizal), as the fungus produces enzyme
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
s that mineralize
Mineralization (biology)
In biology, mineralization refers to the process where an organic substance is converted to an inorganic substance.This may also be a normal biological process which takes place during the life of an organism such as the formation of bone tissue or egg shells, largely with calcium.This term may...
organic compounds and facilitate the transfer of nutrients to the tree.
The ectomycorrhizal structures of H. peckii are among a few in the Bankeraceae
Bankeraceae
The Bankeraceae are a family of fungi in the order Boletales. Taxa are terrestrial, and ectomycorrhizal with species such as Pinaceae or Fagaceae.-External links:*...
that have been studied in detail. They are characterized by a plectenchymatous mantle—a layer of tissue made of hyphae tightly arranged in a parallel orientation, or palisade, and which rarely branch or overlap each other. These hyphae, along with adhering mineral soil particles, are embedded in a gelatinous matrix. The hyphae of the ectomycorrhizae can become chlamydospore
Chlamydospore
A Chlamydospore is the thick-walled big resting spore of several kinds of fungi. It is the life-stage which survives in unfavourable conditions, such as dry or hot seasons....
s, an adaptation that helps the fungus tolerate unfavorable conditions. Chlamydospores of H. peckii have a peculiar structure—markedly distinct from those of other Bankeraceae—with thick, smooth inner walls and an outer wall that is split radially into warts. The most striking characteristic of the ectomycorrhizae as a whole is the way the black outer layers of older sections are shed, giving a "carbonized appearance". The majority of the underground biomass of the fungus is concentrated near the surface, most likely as "mycelial mats"—dense clusters of ectomycorrhizae and mycelium. The mycelium is also known to extend far beyond the site of the fruit bodies, as far as 337 centimetres (11.1 ft) away.
Molecular techniques have been developed to help with conservation efforts of stipitate hydnoid fungi, including H. peckii. While the distribution of the fungus has traditionally been determined by counting the fruit bodies, this method has a major drawback in that fruit bodies are not produced consistently every year, and the absence of fruit bodies is not an indication of the absence of its mycelium in the soil. More modern techniques using the polymerase chain reaction
Polymerase chain reaction
The polymerase chain reaction is a scientific technique in molecular biology to amplify a single or a few copies of a piece of DNA across several orders of magnitude, generating thousands to millions of copies of a particular DNA sequence....
to assess the presence of the fungal DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
in the soil have helped alleviate the issues in monitoring the presence and distribution of fungi mycelia.
Habitat and distribution
The fruit bodies of Hydnellum pecki are found growing solitary, scattered, or clustered together on the ground under conifers, often among mosses and pine needle litter. H. peckii is a "late-stage" fungus that, in boreal forests dominated by jack pineJack Pine
Jack pine is a North American pine with its native range in Canada east of the Rocky Mountains from Northwest Territories to Nova Scotia, and the northeast of the United States from Minnesota to Maine, with the southernmost part of the range just into northwest Indiana...
, typically begins associating with more mature hosts once the canopy has closed. A preference for mountainous
Montane
In biogeography, montane is the highland area located below the subalpine zone. Montane regions generally have cooler temperatures and often have higher rainfall than the adjacent lowland regions, and are frequently home to distinct communities of plants and animals.The term "montane" means "of the...
or subalpine
Subalpine
The subalpine zone is the biotic zone immediately below tree line around the world. Species that occur in this zone depend on the location of the zone on the Earth, for example, Snow Gum in Australia, or Subalpine Larch, Mountain Hemlock and Subalpine Fir in western North America.Trees in the...
ecosystems has been noted.
The fungus has a wide distribution in North America, and is particularly common in the Pacific Northwest
Pacific Northwest
The Pacific Northwest is a region in northwestern North America, bounded by the Pacific Ocean to the west and, loosely, by the Rocky Mountains on the east. Definitions of the region vary and there is no commonly agreed upon boundary, even among Pacific Northwesterners. A common concept of the...
; its range extends north to Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
and east to North Carolina
North Carolina
North Carolina is a state located in the southeastern United States. The state borders South Carolina and Georgia to the south, Tennessee to the west and Virginia to the north. North Carolina contains 100 counties. Its capital is Raleigh, and its largest city is Charlotte...
. In the Puget Sound
Puget Sound
Puget Sound is a sound in the U.S. state of Washington. It is a complex estuarine system of interconnected marine waterways and basins, with one major and one minor connection to the Strait of Juan de Fuca and the Pacific Ocean — Admiralty Inlet being the major connection and...
area of the U.S. state of Washington, it is found in association with Douglas-fir
Douglas-fir
Douglas-fir is one of the English common names for evergreen coniferous trees of the genus Pseudotsuga in the family Pinaceae. Other common names include Douglas tree, and Oregon pine. There are five species, two in western North America, one in Mexico, and two in eastern Asia...
, fir
Fir
Firs are a genus of 48–55 species of evergreen conifers in the family Pinaceae. They are found through much of North and Central America, Europe, Asia, and North Africa, occurring in mountains over most of the range...
, and hemlock
Tsuga
Tsuga is a genus of conifers in the family Pinaceae. The common name hemlock is derived from a perceived similarity in the smell of its crushed foliage to that of the unrelated plant poison hemlock....
. Along the Oregon Coast
Oregon Coast
The Oregon Coast is a region of the U.S. state of Oregon. It runs generally north-south along the Pacific Ocean, forming the western border of the state; the region is bounded to the east by the Oregon Coast Range. The Oregon Coast stretches approximately from the Columbia River in the north to...
it has been collected under lodgepole pine
Lodgepole Pine
Lodgepole Pine, Pinus contorta, also known as Shore Pine, is a common tree in western North America. Like all pines, it is evergreen.-Subspecies:...
. In addition to North America, the mushroom is widespread in Europe, and its presence has been documented in Italy, Germany, and Scotland. The species is common in the latter location, but becoming increasingly rare in several European countries, such as Norway, The Netherlands, and the Czech Republic. Increased pollution in central Europe has been suggested as one possible factor in the mushroom's decline there. Reports from Iran in 2008 and Korea in 2010 were the first outside Europe and North America.
Uses
Although the fruit bodies of H. peckii have been described as resembling "Danish pastry topped with strawberry jam", and Hydnellum species in general are not known to be poisonousMushroom poisoning
Mushroom poisoning refers to harmful effects from ingestion of toxic substances present in a mushroom. These symptoms can vary from slight gastrointestinal discomfort to death. The toxins present are secondary metabolites produced in specific biochemical pathways in the fungal cells...
, they are inedible due to their extremely bitter taste. This acridity persists even in dried specimens.
The fruit bodies of this and other Hydnellum species are prized by mushroom dye
Mushroom dye
Mushrooms can be used to create color dyes.The shingled hedgehog mushroom and related species contain blue-green pigments, which are used for dyeing wool in Norway. The fruiting body of hydnellum peckii can be used to produce a beige colour when no mordant is used, and shades of blue or green...
rs. The colors may range from beige when no mordant
Mordant
A mordant is a substance used to set dyes on fabrics or tissue sections by forming a coordination complex with the dye which then attaches to the fabric or tissue. It may be used for dyeing fabrics, or for intensifying stains in cell or tissue preparations. The term mordant comes from the Latin...
is used, to various shades of blue or green depending on the mordant added.
Chemistry
Screening of an extract of Hydnellum peckii revealed the presence of an effective anticoagulantAnticoagulant
An anticoagulant is a substance that prevents coagulation of blood. A group of pharmaceuticals called anticoagulants can be used in vivo as a medication for thrombotic disorders. Some anticoagulants are used in medical equipment, such as test tubes, blood transfusion bags, and renal dialysis...
, named atromentin (2,5-dihydroxy-3,6-bis(4-hydroxyphenyl
Phenol
Phenol, also known as carbolic acid, phenic acid, is an organic compound with the chemical formula C6H5OH. It is a white crystalline solid. The molecule consists of a phenyl , bonded to a hydroxyl group. It is produced on a large scale as a precursor to many materials and useful compounds...
)-1,4-benzoquinone
1,4-Benzoquinone
1,4-Benzoquinone, commonly known as para-quinone, is a chemical compound with the formula C6H4O2. In a pure state, it forms bright-yellow crystals with a characteristic irritating odor, resembling that of chlorine, bleach, and hot plastic. Impure samples are often dark-colored due to the presence...
), and similar in biological activity
Biological activity
In pharmacology, biological activity or pharmacological activity describes the beneficial or adverse effects of a drug on living matter. When a drug is a complex chemical mixture, this activity is exerted by the substance's active ingredient or pharmacophore but can be modified by the other...
to the well-known anticoagulant heparin
Heparin
Heparin , also known as unfractionated heparin, a highly sulfated glycosaminoglycan, is widely used as an injectable anticoagulant, and has the highest negative charge density of any known biological molecule...
. Atromentin also possesses antibacterial activity, inhibiting the enzyme enoyl-acyl carrier protein reductase
Enoyl-acyl carrier protein reductase
Enoyl-acyl carrier protein reductase , is a key enzyme of the type II fatty acid synthesis system. ENR is an attractive target for narrow-spectrum antibacterial drug discovery because of its essential role in metabolism and its sequence conservation across many bacterial species...
(essential for the biosynthesis of fatty acid
Fatty acid
In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...
s) in the bacteria Streptococcus pneumoniae
Streptococcus pneumoniae
Streptococcus pneumoniae, or pneumococcus, is Gram-positive, alpha-hemolytic, aerotolerant anaerobic member of the genus Streptococcus. A significant human pathogenic bacterium, S...
.
Hydnellum peckii can bioaccumulate
Bioaccumulation
Bioaccumulation refers to the accumulation of substances, such as pesticides, or other organic chemicals in an organism. Bioaccumulation occurs when an organism absorbs a toxic substance at a rate greater than that at which the substance is lost...
the heavy metal caesium
Caesium
Caesium or cesium is the chemical element with the symbol Cs and atomic number 55. It is a soft, silvery-gold alkali metal with a melting point of 28 °C , which makes it one of only five elemental metals that are liquid at room temperature...
. In one Swedish field study, as much as 9% of the total caesium of the topmost 10 cm (3.9 in) of soil was found in the fungal mycelium. In general, ectomycorrhizal fungi, which grow most prolifically in the upper organic horizons of the soil or at the interface between the organic and mineral layers, are involved in the retention and cycling of caesium-137
Caesium-137
Caesium-137 is a radioactive isotope of caesium which is formed as a fission product by nuclear fission.It has a half-life of about 30.17 years, and decays by beta emission to a metastable nuclear isomer of barium-137: barium-137m . Caesium-137 is a radioactive isotope of caesium which is formed...
in organic-rich forest soils.