Collybia cookei
Encyclopedia
Collybia cookei is a species
of fungus
in the Tricholomataceae
family, and one of three species in the genus Collybia
. It is known from Europe, Asia, and North America. The fungus produces fruit bodies
that usually grow on the decomposing remains of other mushroom
s, like Meripilus giganteus
, Inonotus hispidus
, or species of Russula
; occasionally fruit bodies are found on rich humus or well-decayed wood. The fungus produces small white mushrooms with caps
up to 9 mm (0.354330708661417 in) in diameter, supported by thin stems
that originate from a yellowish-brown sclerotium
. The mushroom is difficult to distinguish from the other two species of Collybia unless an effort is made to examine the sclerotia, which is usually buried in the substrate
. The edibility
of the mushroom has not been determined.
in the scientific literature in 1928 as Collybia cirrhata var. cookei by the Italian mycologist Giacomo Bresadola
. In a 1935 publication, Jean D. Arnold reported a series of cultural studies with monokaryon isolates (hypha
having only a single haploid nucleus) of several Collybia
species to determine their mating type
. All attempts to produce hybrids between C. cirrhata var. cookei and C. cirrata or mycelial
fusions between the two species failed. This sexual incompatibility indicated that the two taxa were separate species, and she raised the taxon from varietal to specific
status, calling it Collybia cookei. The species has also been called Microcollybia cookei in a 1979 publication by Joanne Lennox, but the genus Microcollybia has since been folded into Collybia. Marcel Bon
and Régis Courtecuisse considered the species a variety of Collybia tuberosa in a 1988 publication. A 2001 molecular analysis based on the ribosomal DNA
sequences confirmed that C. cookei is phylogenetically related to C. tuberosa and C. cirrhata, and that the three species form a monophyletic group that comprise the genus Collybia.
The specific epithet cookei honors the British mycologist Mordecai Cubitt Cooke
.
of young mushrooms are roughly spherical, but soon become convex to flattened in maturity, and reach diameters of 2 –. The cap margin is rolled or curled inward when young, but straightens out as it matures. The cap color is white to cream. The gills are broadly adnate
to slightly decurrent
, with a color similar to the cap; their spacing is close to subdistant. The whitish stem
is equal in width throughout, usually not straight but with curves, and 2 – long by 0.3 – thick. The upper region of the stem surface can be covered with what appears to be a white powder, and there are thin hairs near the base. The stems originate from a yellowish-brown sclerotium
that is up to 6 mm (0.236220472440945 in) long. The sclerotium ranges in shape from roughly spherical to almond-shaped to irregular, and its surface is often wrinkled and pitted. The mushroom has no distinctive odor or taste, and its edibility
is unknown.
In deposit
, the spore
color is white. The spores are smooth, ellipsoidal to tear-shaped, hyaline
(translucent), not amyloid
, and measure 3.9–5.2 by 2.6–3.3 μm
. The basidia (spore-bearing cells in the hymenium
) are four-spored and hyaline, with dimensions of 16–20 by 4–5 μm. They have clamps at their bases. There are no cystidia on either the edges (cheilocystidia) or faces (pleurocystidia) of the gills. The arrangement of the hypha
e in the hymenophoral
tissue varies from regular to interwoven. The cap cuticle
is a cutis (a type of tissue where the hyphae are arranged more or less parallel to the surface), formed by hyphae with septa
, roughly 4–9 μm in diameter. Clamp connection
s are present in the hyphae. The sclerotium is made of hyphae that have yellow pigment
in their walls that appear in cross-section to be pseudoparenchymatous (compactly interwoven short-celled hyphae that resemble parenchyma
of higher plants), and measure 5–10 μm in diameter.
may be distinguished from C. cookei by its dark brown sclerotia that somewhat resembles an appleseed. Using a microscope
provides a more definitive way of distinguishing the two: the hyphae in the sclerotia of C. cookei are rounded, while those of C. tuberosa are elongated; this diagnostic character is apparent with both fresh and dried material of the two species. C. cirrhata
does not produce sclerotia.
Another mushroom that grows on decomposing fruit bodies is Asterophora lycoperdoides
, which is distinct from C. cookei because of the powdery brown asexual spores (chlamydospore
s) produced on the cap surface. Alexander H. Smith
has noted a general similarity in appearance between C. cookei and the North American species Clitocybe sclerotoidea (then known as Tricholoma sclerotoideum), which is parasitic to Helvella lacunosa
. However, C. sclerotoidea is larger than C. cookei, with cap diameters up to 3 cm (1.2 in), and has more distantly spaced gills.
, Meripilus giganteus
, and Inonotus hispidus
. Fruit bodies occasionally grow on well-decayed wood or rich humus. The fruit bodies grow scattered, clustered, or in groups. A field study conducted near a Brass mill in Sweden revealed that heavy metal contamination had little effect on the appearance of the mushroom, possibly because its substrate
of partially decomposed fruit bodies has a lower metal concentration that the underlying topsoil.
Collybia cookei is found in Europe, Asia (Japan), and North America. The European distribution extends north to the Arctic Circle
and the Lofoten Islands. The species is widely distributed in North America; it was reported from Mexico for the first time in 1998. The fungus is partial to mixed forest dominated by aspen
and conifers in montane
and subalpine
environments. In The Netherlands, it was a component of one of three communities of saprobic fungi associated with roadside verges (the land between the road edge and the adjacent wall, fence or hedge) planted with common oak (Quercus robur); the verges also supported the growth of the mushroom Russula ochroleuca
, a host of C. cookei.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of 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 Tricholomataceae
Tricholomataceae
The Tricholomataceae are a large family of mushrooms within the Agaricales. A classic "wastebasket taxon", the Tricholomataceae is inclusive of any white-, yellow-, or pink-spored genera in the Agaricales not already classified as belonging to the Amanitaceae, Lepiotaceae, Hygrophoraceae,...
family, and one of three species in the genus Collybia
Collybia
Collybia is a genus of mushrooms in the Tricholomataceae family. The genus has a widespread but rare distribution in north temperate areas, and contains three species that grow on the decomposing remains of other mushrooms....
. It is known from Europe, Asia, and North America. The fungus produces 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...
that usually grow on the decomposing remains of other mushroom
Mushroom
A mushroom is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground on soil or on its food source. The standard for the name "mushroom" is the cultivated white button mushroom, Agaricus bisporus; hence the word "mushroom" is most often applied to those fungi that...
s, like Meripilus giganteus
Meripilus giganteus
Meripilus giganteus is a polypore fungus in the Meripilaceae family. It causes a white rot in various types of broadleaved trees, particularly beech , but also Abies, Picea, Pinus, Quercus and Ulmus species...
, Inonotus hispidus
Inonotus hispidus
Inonotus hispidus is a fungus and a plant pathogen.- External links :* *...
, or species of Russula
Russula
Around 750 worldwide species of mycorrhizal mushrooms compose the genus Russula. They are typically common, fairly large, and brightly colored - making them one of the most recognizable genera among mycologists and mushroom collectors...
; occasionally fruit bodies are found on rich humus or well-decayed wood. The fungus produces small white mushrooms with caps
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...
up to 9 mm (0.354330708661417 in) in diameter, supported by thin stems
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...
that originate from a yellowish-brown sclerotium
Sclerotium
A sclerotium is a compact mass of hardened fungal mycelium containing food reserves. One role of sclerotia is to survive environmental extremes. In some higher fungi such as ergot, sclerotia become detached and remain dormant until a favorable opportunity for growth. Other fungi that produce...
. The mushroom is difficult to distinguish from the other two species of Collybia unless an effort is made to examine the sclerotia, which is usually buried in the substrate
Substrate (biology)
In biology a substrate is the surface a plant or animal lives upon and grows on. A substrate can include biotic or abiotic materials and animals. For example, encrusting algae that lives on a rock can be substrate for another animal that lives on top of the algae. See also substrate .-External...
. The edibility
Edible mushroom
Edible mushrooms are the fleshy and edible fruiting bodies of several species of fungi. Mushrooms belong to the macrofungi, because their fruiting structures are large enough to be seen with the naked eye. They can appear either below ground or above ground where they may be picked by hand...
of the mushroom has not been determined.
Taxonomy and phylogeny
The species was first describedSpecies 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...
in the scientific literature in 1928 as Collybia cirrhata var. cookei by the Italian mycologist Giacomo Bresadola
Giacomo Bresadola
Giacomo Bresadola 14 February 1847 – Trento 9 June 1929) was an eminent Italian mycologist. Fungi he named include the deadly Lepiota helveola and Inocybe patouillardii, though the latter is now known as Inocybe erubescens as this latter description predated Bresadola's by a year...
. In a 1935 publication, Jean D. Arnold reported a series of cultural studies with monokaryon isolates (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...
having only a single haploid nucleus) of several Collybia
Collybia
Collybia is a genus of mushrooms in the Tricholomataceae family. The genus has a widespread but rare distribution in north temperate areas, and contains three species that grow on the decomposing remains of other mushrooms....
species to determine their mating type
Mating in fungi
Mating in fungi is a complex process governed by mating types. Research on fungal mating has focused on only a few model species. Since not all of the fungi reproduce sexually and many that do are isogamous, the terms male and female do not apply to this kingdom...
. All attempts to produce hybrids between C. cirrhata var. cookei and C. cirrata or mycelial
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...
fusions between the two species failed. This sexual incompatibility indicated that the two taxa were separate species, and she raised the taxon from varietal to specific
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
status, calling it Collybia cookei. The species has also been called Microcollybia cookei in a 1979 publication by Joanne Lennox, but the genus Microcollybia has since been folded into Collybia. Marcel Bon
Marcel Bon
Marcel Bon is one of France’s best known field mycologists. He was born in Picardy, in 1925 and came to mycology through general botany, and pharmacology...
and Régis Courtecuisse considered the species a variety of Collybia tuberosa in a 1988 publication. A 2001 molecular analysis based on the ribosomal DNA
Ribosomal DNA
Ribosomal DNA codes for ribosomal RNA. The ribosome is an intracellular macromolecule that produces proteins or polypeptide chains. The ribosome itself consists of a composite of proteins and RNA. As shown in the figure, rDNA consists of a tandem repeat of a unit segment, an operon, composed of...
sequences confirmed that C. cookei is phylogenetically related to C. tuberosa and C. cirrhata, and that the three species form a monophyletic group that comprise the genus Collybia.
The specific epithet cookei honors the British mycologist Mordecai Cubitt Cooke
Mordecai Cubitt Cooke
Mordecai Cubitt Cooke was an English botanist and mycologist.Cooke came from a mercantile family in Horning, Norfolk, and worked as an apprentice to a fabric merchant before becoming a clerk in a law firm, but his chief interest was in botany. He founded the Society of Amateur Botanists in 1862...
.
Description
The capsPileus (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...
of young mushrooms are roughly spherical, but soon become convex to flattened in maturity, and reach diameters of 2 –. The cap margin is rolled or curled inward when young, but straightens out as it matures. The cap color is white to cream. The gills are broadly adnate
Adnation
Adnation in plants is the "union of unlike parts; organically united or fused with another dissimilar part, e.g. an ovary to a calyx tube, or stamens to petals". This is in contrast to connation, the fusion of similar organs....
to slightly decurrent
Decurrent
Decurrent is a term used in botany and mycology to describe plant or fungal parts that extend downward.In botany, the term is most often applied to leaf blades that partly wrap or have wings around the stem or petiole and extend down along the stem...
, with a color similar to the cap; their spacing is close to subdistant. The whitish stem
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...
is equal in width throughout, usually not straight but with curves, and 2 – long by 0.3 – thick. The upper region of the stem surface can be covered with what appears to be a white powder, and there are thin hairs near the base. The stems originate from a yellowish-brown sclerotium
Sclerotium
A sclerotium is a compact mass of hardened fungal mycelium containing food reserves. One role of sclerotia is to survive environmental extremes. In some higher fungi such as ergot, sclerotia become detached and remain dormant until a favorable opportunity for growth. Other fungi that produce...
that is up to 6 mm (0.236220472440945 in) long. The sclerotium ranges in shape from roughly spherical to almond-shaped to irregular, and its surface is often wrinkled and pitted. The mushroom has no distinctive odor or taste, and its edibility
Edible mushroom
Edible mushrooms are the fleshy and edible fruiting bodies of several species of fungi. Mushrooms belong to the macrofungi, because their fruiting structures are large enough to be seen with the naked eye. They can appear either below ground or above ground where they may be picked by hand...
is unknown.
In deposit
Spore 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 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...
color is white. The spores are smooth, ellipsoidal to tear-shaped, 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), not 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...
, and measure 3.9–5.2 by 2.6–3.3 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 basidia (spore-bearing cells in the 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...
) are four-spored and hyaline, with dimensions of 16–20 by 4–5 μm. They have clamps at their bases. There are no cystidia on either the edges (cheilocystidia) or faces (pleurocystidia) of the gills. The arrangement of 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 in the hymenophoral
Hymenophore
A hymenophore refers to the hymenium-bearing structure of a fungal fruiting body. Hymenophores can be smooth surfaces, lamellae, folds, tubes, or teeth....
tissue varies from regular to interwoven. The cap cuticle
Pileipellis
thumb|300px||right|The cuticle of some mushrooms, such as [[Russula mustelina]] shown here, can be peeled from the cap, and may be useful as an identification feature....
is a cutis (a type of tissue where the hyphae are arranged more or less parallel to the surface), formed by hyphae with septa
Septum
In anatomy, a septum is a wall, dividing a cavity or structure into smaller ones.-In human anatomy:...
, roughly 4–9 μm in diameter. 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 are present in the hyphae. The sclerotium is made of hyphae that have yellow 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...
in their walls that appear in cross-section to be pseudoparenchymatous (compactly interwoven short-celled hyphae that resemble parenchyma
Parenchyma
Parenchyma is a term used to describe a bulk of a substance. It is used in different ways in animals and in plants.The term is New Latin, f. Greek παρέγχυμα - parenkhuma, "visceral flesh", f. παρεγχεῖν - parenkhein, "to pour in" f. para-, "beside" + en-, "in" + khein, "to pour"...
of higher plants), and measure 5–10 μm in diameter.
Similar species
Collybia cookei is most likely to be confused with the two other members of Collybia, both of which are outwardly similar in appearance; distinguishing between the three typically requires excavating the stem base away from the moss or debris in which the stem is embedded. In the field, C. tuberosaCollybia tuberosa
Collybia tuberosa, commonly known as the lentil shanklet or the appleseed coincap, is an inedible species of fungus in the Tricholomataceae family, and the type species of the genus Collybia. Like the two other members of its genus, it lives on the decomposing remains of other fleshy mushrooms...
may be distinguished from C. cookei by its dark brown sclerotia that somewhat resembles an appleseed. Using a microscope
Optical microscope
The optical microscope, often referred to as the "light microscope", is a type of microscope which uses visible light and a system of lenses to magnify images of small samples. Optical microscopes are the oldest design of microscope and were possibly designed in their present compound form in the...
provides a more definitive way of distinguishing the two: the hyphae in the sclerotia of C. cookei are rounded, while those of C. tuberosa are elongated; this diagnostic character is apparent with both fresh and dried material of the two species. C. cirrhata
Collybia cirrhata
Collybia cirrhata is a species of fungus in the Tricholomataceae family of the Agaricales order . The species was first described in the scientific literature in 1786, but not validly named until 1803. Found in Europe, Northern Eurasia, and North America, it is known from temperate, boreal, and...
does not produce sclerotia.
Another mushroom that grows on decomposing fruit bodies is Asterophora lycoperdoides
Asterophora lycoperdoides
Asterophora lycoperdoides is a species of fungus in the Lyophyllaceae family. It grows as a parasite on other mushrooms, mainly Russulas. Its gills are poorly formed or nearly absent. Asexual spores are produced on the mushrooms cap which enable the organism to clone itself easily...
, which is distinct from C. cookei because of the powdery brown asexual spores (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) produced on the cap surface. Alexander H. Smith
Alexander H. Smith
Alexander Hanchett Smith was an American mycologist known for his extensive contributions to the taxonomy and phylogeny of the higher fungi, especially the agarics.-Early life:...
has noted a general similarity in appearance between C. cookei and the North American species Clitocybe sclerotoidea (then known as Tricholoma sclerotoideum), which is parasitic to Helvella lacunosa
Helvella lacunosa
Helvella lacunosa, also known as the slate grey saddle or fluted black elfin saddle, is an ascomycete fungus of the Helvellaceae family. It is probably the most common Helvella species. The mushroom is readily identified by its irregularly shaped grey cap, fluted stem, and fuzzy undersurfaces...
. However, C. sclerotoidea is larger than C. cookei, with cap diameters up to 3 cm (1.2 in), and has more distantly spaced gills.
Habitat and distribution
Like all members of the genus Collybia, C. cookei grows on the well-rotted, blackened remains of mushrooms, such as species of RussulaRussula
Around 750 worldwide species of mycorrhizal mushrooms compose the genus Russula. They are typically common, fairly large, and brightly colored - making them one of the most recognizable genera among mycologists and mushroom collectors...
, Meripilus giganteus
Meripilus giganteus
Meripilus giganteus is a polypore fungus in the Meripilaceae family. It causes a white rot in various types of broadleaved trees, particularly beech , but also Abies, Picea, Pinus, Quercus and Ulmus species...
, and Inonotus hispidus
Inonotus hispidus
Inonotus hispidus is a fungus and a plant pathogen.- External links :* *...
. Fruit bodies occasionally grow on well-decayed wood or rich humus. The fruit bodies grow scattered, clustered, or in groups. A field study conducted near a Brass mill in Sweden revealed that heavy metal contamination had little effect on the appearance of the mushroom, possibly because its substrate
Substrate (biology)
In biology a substrate is the surface a plant or animal lives upon and grows on. A substrate can include biotic or abiotic materials and animals. For example, encrusting algae that lives on a rock can be substrate for another animal that lives on top of the algae. See also substrate .-External...
of partially decomposed fruit bodies has a lower metal concentration that the underlying topsoil.
Collybia cookei is found in Europe, Asia (Japan), and North America. The European distribution extends north to the Arctic Circle
Arctic Circle
The Arctic Circle is one of the five major circles of latitude that mark maps of the Earth. For Epoch 2011, it is the parallel of latitude that runs north of the Equator....
and the Lofoten Islands. The species is widely distributed in North America; it was reported from Mexico for the first time in 1998. The fungus is partial to mixed forest dominated by aspen
Aspen
Populus section Populus, of the Populus genus, includes the aspen trees and the white poplar Populus alba. The five typical aspens are all native to cold regions with cool summers, in the north of the Northern Hemisphere, extending south at high altitudes in the mountains. The White Poplar, by...
and conifers in montane
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...
and 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...
environments. In The Netherlands, it was a component of one of three communities of saprobic fungi associated with roadside verges (the land between the road edge and the adjacent wall, fence or hedge) planted with common oak (Quercus robur); the verges also supported the growth of the mushroom Russula ochroleuca
Russula ochroleuca
Russula ochroleuca is a member of the genus Russula. A group that have become known as brittlegills. It has been commonly known as the Common Yellow Russula for some years, and latterly the Ochre Brittlegill...
, a host of C. cookei.