Cystoderma carcharias
Encyclopedia
Cystoderma carcharias, is a species of basidiomycete
fungus
of the genus Cystoderma
. A rare fungus, it has a widespread distribution, and has been collected in coniferous forests in Asia, Australia, Europe, and North America. In the field, it can be characterized by a pink cap
up to 6 cm (2.4 in) broad, a well-developed ring
on the stem
, and an unpleasant odour.
, who named it Agaricus carcharias in 1794. Swiss mycologist Victor Fayod
assigned it its current name in 1889. The specific epithet carcharias is probably derived from the Greek καρχαρός (karcharos) which means sharp, pointed or jagged. Interestingly, καρχαρίας (karcharias) is literally translated as shark
.
of Cystoderma carcharias is a relatively small agaric
. The fruiting body is characterised by an off-white and pale pink-tinged cap
with a distinct darker central spot, and a powdery cuticle. The cap is at first convex, but with maturity becomes flat and slightly umbonate. The cap is up to 6 cm (2.4 in) in diameter and may bear a margin fringed with remnants of a partial veil
. The gills are white, adnate and crowded. The stem
is white and smooth above, and granular below a white, upturned, flared and persistent ring
. The stem
is cylindrical and up to 7 cm (2.8 in) tall. The flesh
is white, firm and full throughout. Additionally, C. carcharias forma album is a form recognised as having a snow-white cap.
Under a microscope, the spore
s are seen ellipsoid in shape, with dimensions 4–5.5 by 3–4 µm
. The spores are white and amyloid
. The basidia
are 4-spored, club-shaped, and measure 20–25 by 4–6 µm.
The fruiting body of C. carcharias bears a characteristic strong, unpleasant odour. The odour has been described as earthy, muddy and mouldy by various authors. This has been attributed to the presence of the compound geosmin
. The taste is not distinctive.
Cystoderma carcharias is a rare fungus distributed in Europe, North America and temperate
Asia, occurring only in coniferous forests. It has also been found in Australia. Fruiting bodies are found singly or in groups on soil among grass or moss during late summer and autumn. The fungus is an acidophilic
litter saprotroph
.
This fungus has been deemed inedible by various authors. The unpleasant odour, relatively small fruiting body and sporadic occurrence are probable reasons why this mushroom is regarded as inedible.
Basidiomycota
Basidiomycota is one of two large phyla that, together with the Ascomycota, comprise the subkingdom Dikarya within the Kingdom Fungi...
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...
of the genus Cystoderma
Cystoderma
Cystoderma is a genus of fungi in the family Agaricaceae.The name probably comes from the Greek kýstis meaning pouch and derma meaning skin.-List of species:Below is an incomplete list of Cystoderma species....
. A rare fungus, it has a widespread distribution, and has been collected in coniferous forests in Asia, Australia, Europe, and North America. In the field, it can be characterized by a pink 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...
up to 6 cm (2.4 in) broad, a well-developed ring
Annulus (mycology)
An annulus is the ring like structure sometimes found on the stipe of some species of mushrooms. The annulus represents the remaining part of the partial veil, after it has ruptured to expose the gills or other spore-producing surface. An annulus may be thick and membranous, or it may be cobweb-like...
on 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...
, and an unpleasant odour.
Taxonomy
The species was first described scientifically by Christian Hendrik PersoonChristian Hendrik Persoon
Christiaan Hendrik Persoon was a mycologist who made additions to Linnaeus' mushroom taxonomy.-Early life:...
, who named it Agaricus carcharias in 1794. Swiss mycologist Victor Fayod
Victor Fayod
Victor Fayod was a Swiss mycologist. He is credited with the first description of the mushroom Cystoderma amianthinum. He studied in Lausanne and Zurich. Fayod first worked with Heinrich Anton de Bary in Strasbourg from 1881 to 1882, then as a tutor. He also assisted French bacteriologist André...
assigned it its current name in 1889. The specific epithet carcharias is probably derived from the Greek καρχαρός (karcharos) which means sharp, pointed or jagged. Interestingly, καρχαρίας (karcharias) is literally translated as shark
Shark
Sharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago....
.
Description
The fruiting bodyBasidiocarp
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...
of Cystoderma carcharias is a relatively small agaric
Agaric
An agaric is a type of fungal fruiting body characterized by the presence of a pileus that is clearly differentiated from the stipe , with lamellae on the underside of the pileus. "Agaric" can also refer to a basidiomycete species characterized by an agaric-type fruiting body...
. The fruiting body is characterised by an off-white and pale pink-tinged 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 distinct darker central spot, and a powdery cuticle. The cap is at first convex, but with maturity becomes flat and slightly umbonate. The cap is up to 6 cm (2.4 in) in diameter and may bear a margin fringed with remnants of a partial veil
Partial veil
thumb|150px|right|Developmental stages of [[Agaricus campestris]] showing the role and evolution of a partial veilPartial veil is a mycological term used to describe a temporary structure of tissue found on the fruiting bodies of some basidiomycete fungi, typically agarics...
. The gills are white, adnate and crowded. 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 white and smooth above, and granular below a white, upturned, flared and persistent ring
Annulus (mycology)
An annulus is the ring like structure sometimes found on the stipe of some species of mushrooms. The annulus represents the remaining part of the partial veil, after it has ruptured to expose the gills or other spore-producing surface. An annulus may be thick and membranous, or it may be cobweb-like...
. 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 cylindrical and up to 7 cm (2.8 in) tall. 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 white, firm and full throughout. Additionally, C. carcharias forma album is a form recognised as having a snow-white cap.
Under a microscope, 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...
s are seen ellipsoid in shape, with dimensions 4–5.5 by 3–4 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 white and 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...
. The basidia
Basidium
thumb|right|500px|Schematic showing a basidiomycete mushroom, gill structure, and spore-bearing basidia on the gill margins.A basidium is a microscopic, spore-producing structure found on the hymenophore of fruiting bodies of basidiomycete fungi. The presence of basidia is one of the main...
are 4-spored, club-shaped, and measure 20–25 by 4–6 µm.
The fruiting body of C. carcharias bears a characteristic strong, unpleasant odour. The odour has been described as earthy, muddy and mouldy by various authors. This has been attributed to the presence of the compound geosmin
Geosmin
Geosmin, which literally translates to "earth smell", is an organic compound with a distinct earthy flavour and aroma, and is responsible for the earthy taste of beets and a contributor to the strong scent that occurs in the air when rain falls after a dry spell of weather or when soil is...
. The taste is not distinctive.
Cystoderma carcharias is a rare fungus distributed in Europe, North America and temperate
Temperate
In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally relatively moderate, rather than extreme hot or cold...
Asia, occurring only in coniferous forests. It has also been found in Australia. Fruiting bodies are found singly or in groups on soil among grass or moss during late summer and autumn. The fungus is an acidophilic
Acidophile (organisms)
Acidophilic organisms are those that thrive under highly acidic conditions . These organisms can be found in different branches of the tree of life, including Archaea, Bacteria, and Eukaryotes...
litter saprotroph
Saprotrophic nutrition
Saprotrophic nutrition is a process of chemoheterotrophic extra-cellular digestion involved in the processing of dead or decayed organic matter that occurs in saprotrophs or heterotrophs, and is most often associated with fungi, for example Mucor and Rhizopus...
.
This fungus has been deemed inedible by various authors. The unpleasant odour, relatively small fruiting body and sporadic occurrence are probable reasons why this mushroom is regarded as inedible.
External links
- Scientific images at BioImages (UK)