Suillus pungens
Encyclopedia
Suillus pungens, commonly known as the pungent slippery Jack or the pungent Suillus, is a species
of fungus
in the genus Suillus
. The fruit bodies
of the fungus have slimy convex caps
up to 14 cm (5.5 in) wide. The mushroom is characterized by the very distinct color changes that occur in the cap throughout development. Typically, the young cap is whitish, later becoming grayish-olive to reddish-brown or a mottled combination of these colors. The mushroom has a dotted stem
up to 7 cm (2.8 in) long, and 2 cm (0.78740157480315 in) thick. On the underside on the cap is the spore
-bearing tissue consisting of minute vertically arranged tubes that appear as a surface of angular, yellowish pores. The presence of milky droplets on the pore surface of young individuals, especially in humid environments, is a characteristic feature of this species. S. pungens can usually be distinguished from other similar Suillus species by differences in distribution, odor and taste. The mushroom is considered edible
, but not highly regarded.
An ectomycorrhizal species, S. pungens forms an intimate mutualistic relationship between its underground mycelium
and the young roots of the associated host
tree. The fungus—limited in distribution to California
—fruits almost exclusively with Monterey
and bishop pine
, two trees with small and scattered natural ranges concentrated in the West Coast of the United States
. Several studies have investigated the role of S. pungens in the coastal California
n forest ecosystem it occupies. Although the species produces more fruit bodies than other competing ectomycorrhizal fungi in the same location, it is not a dominant root colonizer, and occupies only a small percentage of ectomycorrhizal root tips. The fungus's propensity to fruit prolifically despite minimal root colonization is a result of its ability to efficiently transfer nutrients from its host for its own use.
scientifically by American mycologists Harry D. Thiers
and Alexander H. Smith
in their 1964 monograph
on North American Suillus species. The type collection was made on the campus of San Francisco State University
in San Francisco. Smith and Thiers classified S. pungens in section Suilli—a grouping of related species characterized by the presence of either a ring
on the stem, a partial veil
adhering to the cap margin, or a "false veil" not attached to the stem but initially covering the tube cavity.
A 1996 molecular analysis of 38 different Suillus species used the sequences of their internal transcribed spacer
s to infer phylogenetic relationships and clarify the taxonomy
of the genus. The results suggest that S. pungens was genetically similar to S. collinitus
, S. neoalbidipes
, S. pseudobrevipes
, S. luteus
, S. brevipes
, S. weaverae, and certain isolates
of S. granulatus
.
The specific epithet is derived from the Latin
pungens, and refers to the pungent aroma of the fruit bodies. The mushroom is commonly
known as the "pungent slippy Jack" or the "pungent Suillus". It has also been referred to as the "slippery Jack" a common name applied to several Suillus species.
of S. pungens is roughly convex when young, becoming plano-convex (flat on one side and rounded on the other) to somewhat flat with age, and reaches diameters of 4 –. The cap surface is sticky to slimy when moist, becoming shiny when dried. The surface is smooth but is sometimes streaked with the sticky glue-like cap slime when older. The cap color is highly variable in this species, and the cap is often variegated
with a mixture of light and dark colors. When young it is dirty-white to olive with pale olive splotches. Maturing caps can retain the color they had when young, or become tawny
to orange-yellow to reddish-brown, or a combination of these colors. The cap margin is initially rolled inward and has a cottony roll of white tissue, but becomes naked and curves downward with age. The flesh
is 1 – thick, white and unchanging in young fruit bodies, frequently changing to yellow when older.
The tubes that comprise the hymenium
(spore-bearing tissue) on the underside of the cap are up to 1 cm (0.393700787401575 in) long, adnate
when young, becoming decurrent or nearly so with age. In young specimens, they are whitish to pale buff, and are covered with milky droplets that become brown to ochraceous
when dried. As specimens mature the color of the pore surface changes to yellowish, and finally to dark yellow. The angular pores, which are 1–1.5 mm in diameter, are not radially arranged, and do not change color when bruised. The stem
is solid (rather than hollow), 3 – long, and 1 – thick near the top. Its shape is variable: either roughly equal in width throughout, thicker at the base, or somewhat thicker in the middle. Its surface is dry and smooth, and covered with irregularly shaped glandular dots. The dots—minute clumps of pigment
ed cells—are initially reddish before becoming brownish. The background color of the stem is initially whitish (roughly the same color as the tubes), but becomes more yellow with age. It does not change color when bruised, and does not have a ring
. The flesh of the stem is white, and does not change color when exposed to air.
The spore print
is olive-brown to pale cinnamon-brown. Individual spore
s are thin-walled, hyaline
(translucent), and smooth. Their shape is ellipsoid to roughly cylindrical in face view, inequilateral when viewed in profile, and they measure 9.5–10 by 2.8–3.5 μm
. The basidia (spore-bearing cells of the hymenium) are hyaline, club-shaped, four-spored, and have dimensions of 33–36 by 8–10 μm. The thin-walled cystidia are rare to scattered on the tube surface but abundant on the pores, where they usually occur in massive clusters. They appear dark brown when mounted in a dilute (3%) solution of potassium hydroxide
(KOH), and are cylindric to roughly club-shaped, measuring 43–79 by 7–10 μm. They are usually encrusted with pigment, although some may be hyaline. The tissue comprising the tube is hyaline, and made of divergent to nearly parallel hyphae that are 3–5 μm wide. The pileipellis
is a tissue type known as an ixotrichodermium (made of interwoven gelatinized hyphae); it stains brown in KOH, and is made of hyphae that are 4–5 μm wide. The stem cuticle is made of clusters of cystidia similar to those found in the hymenium. Clamp connection
s are absent in the hyphae of S. pungens.
Several chemical tests
can be employed in the field to aid in the identification of S. pungens. With an application of a drop of KOH, the flesh will turn vinaceous (the color of red wine), the tubes red, the cap cuticle black, and the stem cuticle pale vinaceous. With ammonium hydroxide
(NH4OH), the flesh becomes very pale vinaceous, and the tubes turn bright red. Iron(II) sulfate
(FeSO4) turns the flesh gray, the tubes dark gray to black, and the stem cuticle light gray.
, but not choice. Its taste is harsh, nauseating, and weakly acidic; the odor is strong and ranges from pleasant, resembling bananas, to pungent. When collecting for the table, young specimens are preferred, as older ones "literally seethe with fat, agitated maggots and sag with so much excess moisture that they practically demand to be wrung out like a sponge!" Michael Kuo's 100 Edible Mushrooms (2007) rates the mushroom's edibility as "bad" and warns that dishes cooked with the mushroom will assume an unpleasant taste.
because of the white color of the young fruit bodies and the droplets of exudate. S. placidus has a wider distribution, is usually found in association with eastern white pine
, is generally smaller, with a maximum cap diameter up to 9 cm (3.5 in), and has smaller spores, measuring 7–9 by 2.5–3.2 μm. It does not have any distinctive taste or odor. S. granulatus
is another potential lookalike species. Its caps are variable in color, ranging from pale yellow to various shades of brown, while the pore surface is initially whitish, later becoming yellowish. Unlike S. pungens, it lacks a characteristic odor and taste. The Californian species S. albidipes lacks the distinctive changes in cap color during development, is associated with lodgepole pine
, has smaller spores (6.6–8.8 by 2.5–3 μm), and also lacks any obvious taste and odor. Another Californian species, Suillus quiescens
, newly described in 2010, may resemble S. pungens—especially older individuals. S. quiescens can be distinguished by a more prominently glandular stem.
relationships almost exclusively with Monterey pine
(Pinus radiata) and bishop pine
(Pinus muricata); some collections have been made under knobcone pine
(Pinus attenuata) and ponderosa pine
(Pinus ponderosa), but only within the range of Monterey pine. All these trees have small scattered natural ranges largely restricted to California
. An EM symbiosis is a mutualistic relationship between an EM fungus and the root tip of a compatible EM plant. The fruit bodies of Suillus pungens grow solitarily, scattered or in groups in humus. They are often found growing near fruit bodies of Chroogomphus vinicolor and Helvella lacunosa
. Suillus pungens is often the most abundant Suillus in the San Francisco Bay Area
. The type collection was made on the campus of San Francisco State University in San Francisco, where it occurs in abundance during the fall and winter seasons. Although it occurs most frequently in the autumn and winter, is one of the few species of Suillus that continue to fruit sporadically throughout the year, especially in wet weather. It has also been identified in the southeastern Sierra Nevada and on Santa Cruz Island
.
A genet is a group of genetically identical individuals that have grown in a given location, all originating vegetatively
from a single ancestor. Once established, genets vegetatively spread hypha
e out from the root tip into the soil and may connect two or more trees to form a network of mycorrhizae. In field studies, the approximate size of fungal genets is typically estimated by collecting and mapping fruit bodies on a site, determining which fruit bodies are genetically identical by either somatic incompatibility (a method fungi use to distinguish self from non-self by delimiting their own mycelia from that of other individuals of the same species) or various molecular
techniques, and then determining the distance between identical fruit bodies. In a 1996 study, mycologists Monique Gardes and Thomas Bruns hypothesized that S. pungens, an abundant fruiter in pine forests, would be dominant on the roots of the pine trees. However, by sampling underground ectomycorrhizae in addition to above-ground fruit bodies, they found that the fungus can fruit prolifically while occupying only a small fraction of the ectomycorrhizal root assemblage, which was otherwise dominated by Russula
species and Tomentella sublilacina. Gardes and Bruns hypothesized that the disparity between above- and below-ground representation may be because the fungus invests less energy in vegetative growth and persistence and more in fruiting, or alternatively, because the species is particularly efficient at acquiring carbon from its hosts and so needs to colonize only a few rootlets to obtain enough to allow abundant fruiting. A 1998 study by Pierluigi Bonello and colleagues used single-strand conformation polymorphism analysis to detect minute genetic differences among S. pungens genets, and showed that most of the fruiting occurred from a single large genet. This result indicates that the fungus persists because of extensive vegetative growth, rather than frequent establishment of new genets from spores, and that it uses carbon resources efficiently. The study also described a S. pungens genet with an area of approximately 300 m² (3,229.2 sq ft) and a span greater than 40 m (131.2 ft) across, which was at the time the largest EM fungal genet reported. The large S. pungens genet was not detected after wildfire, demonstrating that it did not survive in the absence of a host, and suggesting that spores are the primary means by which the fungus recolonizes after a fire.
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 genus Suillus
Suillus
Suillus is a genus of basidiomycete fungi in the family Suillaceae and order Boletales. Species in the genus are associated with coniferous trees, and are mostly distributed in northern temperate locations, although some species have been introduced to the Southern Hemisphere.-Taxonomy:The genus...
. 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...
of the fungus have slimy convex 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 14 cm (5.5 in) wide. The mushroom is characterized by the very distinct color changes that occur in the cap throughout development. Typically, the young cap is whitish, later becoming grayish-olive to reddish-brown or a mottled combination of these colors. The mushroom has a dotted 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...
up to 7 cm (2.8 in) long, and 2 cm (0.78740157480315 in) thick. On the underside on the cap is 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...
-bearing tissue consisting of minute vertically arranged tubes that appear as a surface of angular, yellowish pores. The presence of milky droplets on the pore surface of young individuals, especially in humid environments, is a characteristic feature of this species. S. pungens can usually be distinguished from other similar Suillus species by differences in distribution, odor and taste. The mushroom is considered edible
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...
, but not highly regarded.
An ectomycorrhizal species, S. pungens forms an intimate mutualistic relationship between its underground 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...
and the young roots of the associated 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...
tree. The fungus—limited in distribution to California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
—fruits almost exclusively with Monterey
Monterey Pine
The Monterey Pine, Pinus radiata, family Pinaceae, also known as the Insignis Pine or Radiata Pine is a species of pine native to the Central Coast of California....
and bishop pine
Bishop Pine
The Bishop Pine, Pinus muricata, is a pine with a very restricted range: mostly in the U.S. state of California, including several offshore Channel Islands, and a few locations in Baja California, Mexico...
, two trees with small and scattered natural ranges concentrated in the West Coast of the United States
West Coast of the United States
West Coast or Pacific Coast are terms for the westernmost coastal states of the United States. The term most often refers to the states of California, Oregon, and Washington. Although not part of the contiguous United States, Alaska and Hawaii do border the Pacific Ocean but can't be included in...
. Several studies have investigated the role of S. pungens in the coastal California
Coastal California
Coastal California refers to the coastal regions of the US state of California. The term is not primarily geographical as it also describes an area distinguished by sociological, economical and political attributes...
n forest ecosystem it occupies. Although the species produces more fruit bodies than other competing ectomycorrhizal fungi in the same location, it is not a dominant root colonizer, and occupies only a small percentage of ectomycorrhizal root tips. The fungus's propensity to fruit prolifically despite minimal root colonization is a result of its ability to efficiently transfer nutrients from its host for its own use.
Taxonomy, classification, and phylogeny
The fungus 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...
scientifically by American mycologists Harry D. Thiers
Harry D. Thiers
Harry Delbert Thiers, born January 22, 1919 in Fort McKavett, Texas, died August 8, 2000 in Ohio, was an American mycologist who studied and named a great many fungi of native to North America, particularly California. Thiers taught mycology at San Francisco State University for many years, and a...
and 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:...
in their 1964 monograph
Monograph
A monograph is a work of writing upon a single subject, usually by a single author.It is often a scholarly essay or learned treatise, and may be released in the manner of a book or journal article. It is by definition a single document that forms a complete text in itself...
on North American Suillus species. The type collection was made on the campus of San Francisco State University
San Francisco State University
San Francisco State University is a public university located in San Francisco, California. As part of the 23-campus California State University system, the university offers over 100 areas of study from nine academic colleges...
in San Francisco. Smith and Thiers classified S. pungens in section Suilli—a grouping of related species characterized by the presence of either a 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, 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...
adhering to the cap margin, or a "false veil" not attached to the stem but initially covering the tube cavity.
A 1996 molecular analysis of 38 different Suillus species used the sequences of their 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...
s to infer phylogenetic relationships and clarify the taxonomy
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...
of the genus. The results suggest that S. pungens was genetically similar to S. collinitus
Suillus collinitus
Suillus collinitus is a pored mushroom of the genus Suillus in the Suillaceae family. It is an edible mushroom found in European pine forests. The mushroom has a reddish to chestnut-brown cap that reaches up to in diameter, and a yellow stem measuring up to tall by thick...
, S. neoalbidipes
Suillus neoalbidipes
Suillus neoalbidipes is a species of edible mushroom in the genus Suillus. It was described as a new species by Mary Palm and Elwin Stewart in 1984....
, S. pseudobrevipes
Suillus pseudobrevipes
Suillus pseudobrevipes is a species of edible mushroom in the genus Suillus. It was first described scientifically by American mycologists Harry D. Thiers and Alexander H. Smith in 1964....
, S. luteus
Suillus luteus
Suillus luteus is a basidiomycete fungus, and the type species of the genus Suillus. It is a common fungus indigenous to coniferous forests of Eurasia and North America, and introduced to southern Australia and New Zealand...
, S. brevipes
Suillus brevipes
Suillus brevipes is a species of fungus in the Boletaceae family. First described by American mycologists in the late 19th century, it is commonly known as the stubby-stalk or the short-stemmed slippery Jack...
, S. weaverae, and certain isolates
Genetic isolate
A genetic isolate is population of organisms that has little genetic mixing with other organisms within the same species. This may result in speciation, but this is not necessarily the case...
of S. granulatus
Suillus granulatus
Suillus granulatus is a pored mushroom of the genus Suillus in the Suillaceae family. It is similar to the related S. luteus, but can be distinguished by its ringless stalk. Like S. luteus, it is an edible mushroom that often grows in a symbiosis with pine...
.
The specific epithet 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...
pungens, and refers to the pungent aroma of the fruit bodies. 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 "pungent slippy Jack" or the "pungent Suillus". It has also been referred to as the "slippery Jack" a common name applied to several Suillus species.
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 S. pungens is roughly convex when young, becoming plano-convex (flat on one side and rounded on the other) to somewhat flat with age, and reaches diameters of 4 –. The cap surface is sticky to slimy when moist, becoming shiny when dried. The surface is smooth but is sometimes streaked with the sticky glue-like cap slime when older. The cap color is highly variable in this species, and the cap is often variegated
Variegation
Variegation is the appearance of differently coloured zones in the leaves, and sometimes the stems, of plants. This may be due to a number of causes...
with a mixture of light and dark colors. When young it is dirty-white to olive with pale olive splotches. Maturing caps can retain the color they had when young, or become tawny
Tawny (color)
Tawny is a yellowish brown color. The word means "tan-colored," from Anglo-Norman tauné "associated with the brownish-yellow of tanned leather," from Old French tané "to tan hides," from Medieval Latin tannare, from tannum "crushed oak bark," used in tanning leather, probably from a Celtic source...
to orange-yellow to reddish-brown, or a combination of these colors. The cap margin is initially rolled inward and has a cottony roll of white tissue, but becomes naked and curves downward with age. 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 1 – thick, white and unchanging in young fruit bodies, frequently changing to yellow when older.
The tubes that comprise 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...
(spore-bearing tissue) on the underside of the cap are up to 1 cm (0.393700787401575 in) long, 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....
when young, becoming decurrent or nearly so with age. In young specimens, they are whitish to pale buff, and are covered with milky droplets that become brown to ochraceous
Ochre
Ochre is the term for both a golden-yellow or light yellow brown color and for a form of earth pigment which produces the color. The pigment can also be used to create a reddish tint known as "red ochre". The more rarely used terms "purple ochre" and "brown ochre" also exist for variant hues...
when dried. As specimens mature the color of the pore surface changes to yellowish, and finally to dark yellow. The angular pores, which are 1–1.5 mm in diameter, are not radially arranged, and do not change color when bruised. 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 solid (rather than hollow), 3 – long, and 1 – thick near the top. Its shape is variable: either roughly equal in width throughout, thicker at the base, or somewhat thicker in the middle. Its surface is dry and smooth, and covered with irregularly shaped glandular dots. The dots—minute clumps of 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...
ed cells—are initially reddish before becoming brownish. The background color of the stem is initially whitish (roughly the same color as the tubes), but becomes more yellow with age. It does not change color when bruised, and does not have a 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 flesh of the stem is white, and does not change color when exposed to air.
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 olive-brown to pale cinnamon-brown. 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 thin-walled, 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), and smooth. Their shape is ellipsoid to roughly cylindrical in face view, inequilateral when viewed in profile, and they measure 9.5–10 by 2.8–3.5 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 of the hymenium) are hyaline, club-shaped, four-spored, and have dimensions of 33–36 by 8–10 μm. The thin-walled cystidia are rare to scattered on the tube surface but abundant on the pores, where they usually occur in massive clusters. They appear dark brown when mounted in a dilute (3%) 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...
(KOH), and are cylindric to roughly club-shaped, measuring 43–79 by 7–10 μm. They are usually encrusted with pigment, although some may be hyaline. The tissue comprising the tube is hyaline, and made of divergent to nearly parallel hyphae that are 3–5 μm wide. The pileipellis
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 tissue type known as an ixotrichodermium (made of interwoven gelatinized hyphae); it stains brown in KOH, and is made of hyphae that are 4–5 μm wide. The stem cuticle is made of clusters of cystidia similar to those found in the hymenium. 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 absent in the hyphae of S. pungens.
Several chemical tests
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...
can be employed in the field to aid in the identification of S. pungens. With an application of a drop of KOH, the flesh will turn vinaceous (the color of red wine), the tubes red, the cap cuticle black, and the stem cuticle pale vinaceous. With ammonium hydroxide
Ammonium hydroxide
Ammonia solution, also known as ammonium hydroxide, ammonia water, ammonical liquor, ammonia liquor, aqua ammonia, aqueous ammonia, or simply ammonia, is a solution of ammonia in water. It can be denoted by the symbols NH3...
(NH4OH), the flesh becomes very pale vinaceous, and the tubes turn bright red. Iron(II) sulfate
Iron(II) sulfate
Iron sulfate or ferrous sulfate is the chemical compound with the formula FeSO4. Known since ancient times as copperas and as green vitriol, the blue-green heptahydrate is the most common form of this material...
(FeSO4) turns the flesh gray, the tubes dark gray to black, and the stem cuticle light gray.
Edibility
The mushroom is considered edibleEdible 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...
, but not choice. Its taste is harsh, nauseating, and weakly acidic; the odor is strong and ranges from pleasant, resembling bananas, to pungent. When collecting for the table, young specimens are preferred, as older ones "literally seethe with fat, agitated maggots and sag with so much excess moisture that they practically demand to be wrung out like a sponge!" Michael Kuo's 100 Edible Mushrooms (2007) rates the mushroom's edibility as "bad" and warns that dishes cooked with the mushroom will assume an unpleasant taste.
Similar species
Suillus pungens is characterized by the very distinct color changes that occur in the cap as it develops. The range of color variation makes it possible to misidentify the species with others whose color overlaps. Suillus pungens has been misidentified as S. placidusSuillus placidus
Suillus placidus, is a species of fungus in the genus Suillus. It is an edible pored mushroom found in European and North American coniferous forests, growing in association with several species of pine of the subgenus Strobus.-Description:...
because of the white color of the young fruit bodies and the droplets of exudate. S. placidus has a wider distribution, is usually found in association with eastern white pine
Eastern White Pine
Pinus strobus, commonly known as the eastern white pine, is a large pine native to eastern North America, occurring from Newfoundland west to Minnesota and southeastern Manitoba, and south along the Appalachian Mountains to the northern edge of Georgia.It is occasionally known as simply white pine,...
, is generally smaller, with a maximum cap diameter up to 9 cm (3.5 in), and has smaller spores, measuring 7–9 by 2.5–3.2 μm. It does not have any distinctive taste or odor. S. granulatus
Suillus granulatus
Suillus granulatus is a pored mushroom of the genus Suillus in the Suillaceae family. It is similar to the related S. luteus, but can be distinguished by its ringless stalk. Like S. luteus, it is an edible mushroom that often grows in a symbiosis with pine...
is another potential lookalike species. Its caps are variable in color, ranging from pale yellow to various shades of brown, while the pore surface is initially whitish, later becoming yellowish. Unlike S. pungens, it lacks a characteristic odor and taste. The Californian species S. albidipes lacks the distinctive changes in cap color during development, is associated with 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:...
, has smaller spores (6.6–8.8 by 2.5–3 μm), and also lacks any obvious taste and odor. Another Californian species, Suillus quiescens
Suillus quiescens
Suillus quiescens is a pored mushroom of the genus Suillus in the family Suillaceae. First collected in 2002 on Santa Cruz Island off the coast of California, in association with Bishop Pine , the species was scientifically described and named in 2010...
, newly described in 2010, may resemble S. pungens—especially older individuals. S. quiescens can be distinguished by a more prominently glandular stem.
Ecology, habitat and distribution
Suillus pungens is an ectomycorrhizal (EM) basidiomycete that forms symbioticSymbiosis
Symbiosis is close and often long-term interaction between different biological species. In 1877 Bennett used the word symbiosis to describe the mutualistic relationship in lichens...
relationships almost exclusively with Monterey pine
Monterey Pine
The Monterey Pine, Pinus radiata, family Pinaceae, also known as the Insignis Pine or Radiata Pine is a species of pine native to the Central Coast of California....
(Pinus radiata) and bishop pine
Bishop Pine
The Bishop Pine, Pinus muricata, is a pine with a very restricted range: mostly in the U.S. state of California, including several offshore Channel Islands, and a few locations in Baja California, Mexico...
(Pinus muricata); some collections have been made under knobcone pine
Knobcone Pine
The Knobcone Pine, Pinus attenuata, is a tree that grows in mild climates on poor soils. It ranges from the mountains of southern Oregon to Baja California with the greatest concentration in northern California and the Oregon-California border....
(Pinus attenuata) and ponderosa pine
Ponderosa Pine
Pinus ponderosa, commonly known as the Ponderosa Pine, Bull Pine, Blackjack Pine, or Western Yellow Pine, is a widespread and variable pine native to western North America. It was first described by David Douglas in 1826, from eastern Washington near present-day Spokane...
(Pinus ponderosa), but only within the range of Monterey pine. All these trees have small scattered natural ranges largely restricted to California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
. An EM symbiosis is a mutualistic relationship between an EM fungus and the root tip of a compatible EM plant. The fruit bodies of Suillus pungens grow solitarily, scattered or in groups in humus. They are often found growing near fruit bodies of Chroogomphus vinicolor and 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...
. Suillus pungens is often the most abundant Suillus in the San Francisco Bay Area
San Francisco Bay Area
The San Francisco Bay Area, commonly known as the Bay Area, is a populated region that surrounds the San Francisco and San Pablo estuaries in Northern California. The region encompasses metropolitan areas of San Francisco, Oakland, and San Jose, along with smaller urban and rural areas...
. The type collection was made on the campus of San Francisco State University in San Francisco, where it occurs in abundance during the fall and winter seasons. Although it occurs most frequently in the autumn and winter, is one of the few species of Suillus that continue to fruit sporadically throughout the year, especially in wet weather. It has also been identified in the southeastern Sierra Nevada and on Santa Cruz Island
Santa Cruz Island
Santa Cruz Island was the largest privately owned island off the continental United States, but is currently part-owned by the National Park service . The island, located off the coast of California, is long and from wide...
.
A genet is a group of genetically identical individuals that have grown in a given location, all originating vegetatively
Vegetative reproduction
Vegetative reproduction is a form of asexual reproduction in plants. It is a process by which new individuals arise without production of seeds or spores...
from a single ancestor. Once established, genets vegetatively spread 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 out from the root tip into the soil and may connect two or more trees to form a network of mycorrhizae. In field studies, the approximate size of fungal genets is typically estimated by collecting and mapping fruit bodies on a site, determining which fruit bodies are genetically identical by either somatic incompatibility (a method fungi use to distinguish self from non-self by delimiting their own mycelia from that of other individuals of the same species) or various molecular
Molecular biology
Molecular biology is the branch of biology that deals with the molecular basis of biological activity. This field overlaps with other areas of biology and chemistry, particularly genetics and biochemistry...
techniques, and then determining the distance between identical fruit bodies. In a 1996 study, mycologists Monique Gardes and Thomas Bruns hypothesized that S. pungens, an abundant fruiter in pine forests, would be dominant on the roots of the pine trees. However, by sampling underground ectomycorrhizae in addition to above-ground fruit bodies, they found that the fungus can fruit prolifically while occupying only a small fraction of the ectomycorrhizal root assemblage, which was otherwise dominated by 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...
species and Tomentella sublilacina. Gardes and Bruns hypothesized that the disparity between above- and below-ground representation may be because the fungus invests less energy in vegetative growth and persistence and more in fruiting, or alternatively, because the species is particularly efficient at acquiring carbon from its hosts and so needs to colonize only a few rootlets to obtain enough to allow abundant fruiting. A 1998 study by Pierluigi Bonello and colleagues used single-strand conformation polymorphism analysis to detect minute genetic differences among S. pungens genets, and showed that most of the fruiting occurred from a single large genet. This result indicates that the fungus persists because of extensive vegetative growth, rather than frequent establishment of new genets from spores, and that it uses carbon resources efficiently. The study also described a S. pungens genet with an area of approximately 300 m² (3,229.2 sq ft) and a span greater than 40 m (131.2 ft) across, which was at the time the largest EM fungal genet reported. The large S. pungens genet was not detected after wildfire, demonstrating that it did not survive in the absence of a host, and suggesting that spores are the primary means by which the fungus recolonizes after a fire.