Collybia tuberosa
Encyclopedia
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 mushroom
s. The fungus produces small whitish fruit bodies
with caps
up to 1 cm (0.393700787401575 in) wide held by thin stems
up to 5 cm (2 in) long. On the underside of the cap are closely spaced white gills that are broadly attached to the stem. At the base of the stem, embedded in the substrate
is a small reddish-brown sclerotium
that somewhat resembles an apple seed. The appearance of the sclerotium distinguishes it from the other two species of Collybia, which are otherwise very similar in overall appearance. C. tuberosa is found in Europe, North America, and Japan, growing in dense clusters on species of Lactarius
and Russula
, bolete
s, hydnum
s, and polypore
s.
in the 6th volume of his Herbier de la France (1786). Christian Hendrik Persoon
called it Agaricus amanitae subsp.
tuberosus in his 1799 publication Observationes Mycologicae, while Samuel Frederick Gray
referred it to Gymnopus
in 1821. It was transferred to Collybia
by Paul Kummer
in 1886. The species has also been called Microcollybia tuberata in a 1979 publication by Joanne Lennox, but the genus Microcollybia has since been folded into Collybia. Additional taxonomic synonyms
include Marasmius sclerotipes Bres. 1881, Chamaeceras sclerotipes (Bres.) Kuntze 1898, and Collybia sclerotipes (Bres.) S.Ito 1950.
Molecular phylogenetic analysis reported in 2001 used RNA sequences to establish that C. tuberosa forms a monophyletic group with C. cookei
and C. cirrhata
; this finding was later corroborated in a 2006 publication.
The specific epithet tuberosa is derived from the Latin
word for "tuberous". The mushroom is commonly
known as the "lentil shanklet", or the "appleseed coincap". Samuel Gray called it the "tuberous naked-foot" in his 1821 Natural Arrangement of British plants.
of C. tuberosa ranges in shape from obtusely convex to cushion-shaped with a margin curved inward when young, to flattened in age, with margin curved downward to straight. The cap sometimes has a shallow depression in the center, or a shallow umbo
. Its diameter is small, reaching a maximum of 10 mm (0.393700787401575 in). The cap surface is dry to moist, smooth to covered with fine soft hairs, and somewhat hygrophanous
—changing color depending on the level of hydration. Sometimes the cap margin is pleated or grooved. The center of the cap is pinkish-buff but whitish around the margin, and it becomes whitish overall as it matures. The flesh
is thin, and colored whitish to light buff. The mushroom has no distinctive taste or odor, and is considered inedible.
The gills are adnate
(bluntly fused to the stem), becoming subdecurrent with age (running slightly down the length of the stem). The gill spacing is close to subdistant, and the individual gills are whitish to pinkish-buff, thin, narrow to moderately broad, and have straight edges. The stem
is 10 – long by 1 –, and roughly equal in width throughout its length. It is slender and thread-like, flexible and pliant, with a dry surface. The top of the stem is covered with scales or a fine whitish powder, while the lower portion has hairs ranging from delicate to coarse. The color of the stem is generally whitish to pinkish-buff, but it darkens after it has been handled. The stem interior is pith
y, and becomes hollow with age. The stems originate from a dark reddish-brown sclerotium
of variable shape, typically measuring 3 – by 2 –. The surface of the sclerotium is initially smooth, but later becomes wrinkled or furrowed; its interior is solid and white. It is often compared to an apple seed in appearance. Typically, several sclerotia are connected by thin strands of mycelia
. The sclerotium is a resting structure that allows to fungus to overwinter in its host. In 1915, William Murrill
reported the sclerotia of C. tuberosa to be bioluminescent.
The spore print
is white. Individual spore
s are smooth, ellipsoid to tear-shaped in profile, obovoid to ellipsoid or cylindric in face or back view, with dimensions of 4.2–6.2 by 2.8–3.5µm
. They are inamyloid
and acyanophilous (non-reactive to staining with Melzer's reagent
and Methyl blue
, respectively). The basidia (spore-bearing cells in the hymenium
) are club-shaped to cylindric and 15.4–21 by 3.5–5 µm. The cheilocystidia (cystidia on the gill edge) are scattered to infrequent, inconspicuous, and 17.5–31.5 µm long. Their shape ranges from a contorted cylinder to roughly club-shaped to irregularly diverticulate (with short offshoots approximately at right angles to the main stem). There are no pleurocystidia (cystidia on the gill face). The gill tissue is made of interwoven hyphae that are non-reactive to Melzer's reagent. These hyphae are smooth and thin-walled, measuring 2.8–6.4 µm in diameter. The cap tissue is made of hyphae that is interwoven below the center of the cap, radially oriented over the gills, and inamyloid. These hyphae are smooth, thin-walled, and 2.8–7 µm in diameter. The cap cuticle
is a thin layer of smooth thin-walled hyphae that are more or less radially oriented, bent-over, cylindric and somewhat gelatinous, measuring 2–5 µm in diameter; they are occasionally diverticulate. The cuticle of the stem is made of a layer of parallel, vertically oriented smooth, thin-walled hyphae that are 2–4.2 µm in diameter, pale yellowish brown in alkali mounting solution. The stem has moderately thin-walled and smooth cystidia that are resemble flexuous or contorted cylinders. They are hyaline
in alkali, and 3.5–7 µm in diameter. Clamp connection
s are present in the hyphae of all tissues.
is similar in size and appearance to C. tuberosa, but grows on spruce
and Douglas-fir
cones. The "Magnolia coincap" (Strobilurus conigenoides) is smaller and grows on the cones of Magnolia
s. The two remaining Collybia species closely resemble C. tuberosa, but can be distinguished by examining the stem bases at the point of attachment into the substrate. C. cookei has roughly spherical, light brown to yellowish sclerotia, while C. cirrhata does not produce sclerotia. In the field, C. tuberosa may be distinguished from C. cookei by its dark reddish-brown sclerotia that somewhat resembles an appleseed. 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. In contrast, C. cirrhata
does not produce sclerotia.
, and needs the host
to be living, or whether it is saprobic. Either way, the fruit bodies of the fungus are found growing solitarily or in dense clusters on the decomposing, often blackened remains of other mushrooms. Hosts include agarics
(particularly Lactarius
and Russula
), bolete
s, hydnum
s, and polypore
s. In the Pacific Northwest
region of the United States, Russula crassotunicata is a common and abundant species that has been definitively identified as a host of both C. tuberosa and Dendrocollybia racemosa. The Russula fruit bodies are slow to decay, and are available nearly year-round as a substrate for the saprobes. Based on field observations, the authors suggest that C. tuberosa may produce fruit bodies on less decayed mushrooms, while D. racemosa produces them on much more heavily decayed mushrooms.
Collybia tuberosa is found in Europe and North America, and in most common in the summer and autumn, coinciding with the fruiting periods of other mushrooms. It has also been reported from Japan.
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 the type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
of 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....
. Like the two other members of its genus, it lives on the decomposing remains of other fleshy 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. The fungus produces small whitish 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...
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 1 cm (0.393700787401575 in) wide held 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...
up to 5 cm (2 in) long. On the underside of the cap are closely spaced white gills that are broadly attached to the stem. At the base of the stem, embedded 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...
is a small reddish-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 somewhat resembles an apple seed. The appearance of the sclerotium distinguishes it from the other two species of Collybia, which are otherwise very similar in overall appearance. C. tuberosa is found in Europe, North America, and Japan, growing in dense clusters on species of Lactarius
Lactarius
Lactarius is a genus of mushroom-producing fungi. The genus, collectively known commonly as milk-caps, are characterized by the fact that they exude a milky fluid if cut or damaged...
and 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...
, bolete
Bolete
A bolete is a type of fungal fruiting body characterized by the presence of a pileus that is clearly differentiated from the stipe, with a spongy surface of pores on the underside of the pileus...
s, 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...
s, and polypore
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...
s.
Taxonomy, phylogeny, and naming
The species was first described under the name Agaricus tuberosus by the French naturalist Jean BulliardJean Baptiste François Pierre Bulliard
Jean Baptiste François Pierre Bulliard was a French physician and botanist....
in the 6th volume of his Herbier de la France (1786). Christian Hendrik Persoon
Christian Hendrik Persoon
Christiaan Hendrik Persoon was a mycologist who made additions to Linnaeus' mushroom taxonomy.-Early life:...
called it Agaricus amanitae subsp.
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
tuberosus in his 1799 publication Observationes Mycologicae, while Samuel Frederick Gray
Samuel Frederick Gray
Samuel Frederick Gray was a British botanist, mycologist, and pharmacologist. He was the father of the zoologists John Edward Gray and George Robert Gray.-Background:...
referred it to Gymnopus
Gymnopus
Gymnopus is a genus of fungus in the Marasmiaceae family. The genus has a widespread distribution and contains about 300 species.-Representative species:*Gymnopus dryophilus*Gymnopus fusipes*Gymnopus peronatus*Gymnopus semihirtipes...
in 1821. It was transferred to 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....
by Paul Kummer
Paul Kummer
Paul Kummer was a priest, teacher, and scientist in Zerbst, Germany, known chiefly for his contribution to mycological nomenclature. Earlier classification of agarics by pioneering fungal taxonomist Elias Magnus Fries designated only a very small number of genera, with most species falling into...
in 1886. The species has also been called Microcollybia tuberata in a 1979 publication by Joanne Lennox, but the genus Microcollybia has since been folded into Collybia. Additional taxonomic synonyms
Synonym (taxonomy)
In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...
include Marasmius sclerotipes Bres. 1881, Chamaeceras sclerotipes (Bres.) Kuntze 1898, and Collybia sclerotipes (Bres.) S.Ito 1950.
Molecular phylogenetic analysis reported in 2001 used RNA sequences to establish that C. tuberosa forms a monophyletic group with C. cookei
Collybia cookei
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...
and 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...
; this finding was later corroborated in a 2006 publication.
The specific epithet tuberosa is derived from the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
word for "tuberous". The mushroom is commonly
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...
known as the "lentil shanklet", or the "appleseed coincap". Samuel Gray called it the "tuberous naked-foot" in his 1821 Natural Arrangement of British plants.
Description
The capPileus (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 C. tuberosa ranges in shape from obtusely convex to cushion-shaped with a margin curved inward when young, to flattened in age, with margin curved downward to straight. The cap sometimes has a shallow depression in the center, or a shallow umbo
Umbo (mycology)
thumb|right|[[Cantharellula umbonata]] has an umbo.thumb|right|The cap of [[Psilocybe makarorae]] is acutely papillate.An umbo is a raised area in the center of a mushroom cap. Caps that possess this feature are called umbonate. Umbos that are sharply pointed are called acute, while those that are...
. Its diameter is small, reaching a maximum of 10 mm (0.393700787401575 in). The cap surface is dry to moist, smooth to covered with fine soft hairs, and somewhat hygrophanous
Hygrophanous
The adjective hygrophanous refers to the color change of mushroom tissue as it loses or absorbs water, which causes the pileipellis to become more transparent when wet and opaque when dry....
—changing color depending on the level of hydration. Sometimes the cap margin is pleated or grooved. The center of the cap is pinkish-buff but whitish around the margin, and it becomes whitish overall as it matures. 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 thin, and colored whitish to light buff. The mushroom has no distinctive taste or odor, and is considered inedible.
The gills are 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....
(bluntly fused to the stem), becoming subdecurrent with age (running slightly down the length of the stem). The gill spacing is close to subdistant, and the individual gills are whitish to pinkish-buff, thin, narrow to moderately broad, and have straight edges. The 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 10 – long by 1 –, and roughly equal in width throughout its length. It is slender and thread-like, flexible and pliant, with a dry surface. The top of the stem is covered with scales or a fine whitish powder, while the lower portion has hairs ranging from delicate to coarse. The color of the stem is generally whitish to pinkish-buff, but it darkens after it has been handled. The stem interior is pith
Pith
Pith, or medulla, is a tissue in the stems of vascular plants. Pith is composed of soft, spongy parenchyma cells, which store and transport nutrients throughout the plant. In eudicots, pith is located in the center of the stem. In monocots, it extends also into flowering stems and roots...
y, and becomes hollow with age. The stems originate from a dark reddish-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...
of variable shape, typically measuring 3 – by 2 –. The surface of the sclerotium is initially smooth, but later becomes wrinkled or furrowed; its interior is solid and white. It is often compared to an apple seed in appearance. Typically, several sclerotia are connected by thin strands of mycelia
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...
. The sclerotium is a resting structure that allows to fungus to overwinter in its host. In 1915, William Murrill
William Murrill
William Alphonso Murrill was an American mycologist, known for his contributions to the knowledge of the Agaricales and Polyporaceae.- Education :...
reported the sclerotia of C. tuberosa to be bioluminescent.
The spore print
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...
is white. Individual 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 smooth, ellipsoid to tear-shaped in profile, obovoid to ellipsoid or cylindric in face or back view, with dimensions of 4.2–6.2 by 2.8–3.5µm
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...
. They are inamyloid
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 acyanophilous (non-reactive to staining 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:...
and Methyl 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...
, respectively). 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 club-shaped to cylindric and 15.4–21 by 3.5–5 µm. The cheilocystidia (cystidia on the gill edge) are scattered to infrequent, inconspicuous, and 17.5–31.5 µm long. Their shape ranges from a contorted cylinder to roughly club-shaped to irregularly diverticulate (with short offshoots approximately at right angles to the main stem). There are no pleurocystidia (cystidia on the gill face). The gill tissue is made of interwoven hyphae that are non-reactive to Melzer's reagent. These hyphae are smooth and thin-walled, measuring 2.8–6.4 µm in diameter. The cap tissue is made of hyphae that is interwoven below the center of the cap, radially oriented over the gills, and inamyloid. These hyphae are smooth, thin-walled, and 2.8–7 µm in diameter. 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 thin layer of smooth thin-walled hyphae that are more or less radially oriented, bent-over, cylindric and somewhat gelatinous, measuring 2–5 µm in diameter; they are occasionally diverticulate. The cuticle of the stem is made of a layer of parallel, vertically oriented smooth, thin-walled hyphae that are 2–4.2 µm in diameter, pale yellowish brown in alkali mounting solution. The stem has moderately thin-walled and smooth cystidia that are resemble flexuous or contorted cylinders. They 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...
in alkali, and 3.5–7 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 of all tissues.
Similar species
Baeospora myosuraBaeospora myosura
Baeospora myosura is a species of fungus that produces mushrooms with long, coarse hairs. It grows on plant material and manure. It is white to cream and the spore color is white, cream, or yellowish. It is commonly found in North America and Europe. The common name of the mushroom is conifercone...
is similar in size and appearance to C. tuberosa, but grows on spruce
Spruce
A spruce is a tree of the genus Picea , a genus of about 35 species of coniferous evergreen trees in the Family Pinaceae, found in the northern temperate and boreal regions of the earth. Spruces are large trees, from tall when mature, and can be distinguished by their whorled branches and conical...
and 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...
cones. The "Magnolia coincap" (Strobilurus conigenoides) is smaller and grows on the cones of Magnolia
Magnolia
Magnolia is a large genus of about 210 flowering plant species in the subfamily Magnolioideae of the family Magnoliaceae. It is named after French botanist Pierre Magnol....
s. The two remaining Collybia species closely resemble C. tuberosa, but can be distinguished by examining the stem bases at the point of attachment into the substrate. C. cookei has roughly spherical, light brown to yellowish sclerotia, while C. cirrhata does not produce sclerotia. In the field, C. tuberosa may be distinguished from C. cookei by its dark reddish-brown sclerotia that somewhat resembles an appleseed. 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. In contrast, 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.
Habitat and distribution
It is not known if C. tuberosa is strictly parasiticParasitism
Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Traditionally parasite referred to organisms with lifestages that needed more than one host . These are now called macroparasites...
, and needs the host
Host (biology)
In biology, a host is an organism that harbors a parasite, or a mutual or commensal symbiont, typically providing nourishment and shelter. In botany, a host plant is one that supplies food resources and substrate for certain insects or other fauna...
to be living, or whether it is saprobic. Either way, the fruit bodies of the fungus are found growing solitarily or in dense clusters on the decomposing, often blackened remains of other mushrooms. Hosts include agarics
Agaricales
The fungal order Agaricales, also known as gilled mushrooms , or euagarics, contains some of the most familiar types of mushrooms. The order has 33 extant families, 413 genera, and over 13000 described species, along with five extinct genera known only from the fossil record...
(particularly Lactarius
Lactarius
Lactarius is a genus of mushroom-producing fungi. The genus, collectively known commonly as milk-caps, are characterized by the fact that they exude a milky fluid if cut or damaged...
and 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...
), bolete
Bolete
A bolete is a type of fungal fruiting body characterized by the presence of a pileus that is clearly differentiated from the stipe, with a spongy surface of pores on the underside of the pileus...
s, 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...
s, and polypore
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...
s. 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...
region of the United States, Russula crassotunicata is a common and abundant species that has been definitively identified as a host of both C. tuberosa and Dendrocollybia racemosa. The Russula fruit bodies are slow to decay, and are available nearly year-round as a substrate for the saprobes. Based on field observations, the authors suggest that C. tuberosa may produce fruit bodies on less decayed mushrooms, while D. racemosa produces them on much more heavily decayed mushrooms.
Collybia tuberosa is found in Europe and North America, and in most common in the summer and autumn, coinciding with the fruiting periods of other mushrooms. It has also been reported from Japan.