Lactarius subflammeus
Encyclopedia
Lactarius subflammeus, commonly known as the orange milk cap, is a species of fungus
in the Russulaceae
family. It is found in western North America in the late summer and fall and is especially common in the Pacific Northwest
, where it grows on the ground near conifers like pine
and spruce
. The brightly colored fruit bodies
, which are slimy or sticky, have scarlet caps
when young that soon fade to brilliant orange. The stem
—typically longer than the width of the cap—is also bright orange but the gills are whitish. The mushroom secretes a whitish latex
when it is cut or injured.
and Alexander H. Smith
in their 1979 monograph
of North American species of the genus Lactarius
, based on specimens collected from Pacific City, Oregon
. Prior to this description, the species had frequently been confused in the literature with L. aurantiacus. The specific epithet subflammeus means "almost flame color". It is classified in the section
Russularia of the subgenus
Russularia of Lactarius. Species in this subgenus have small to medium-sized and fragile fruit bodies.
Lactarius subflammeus is commonly
known as the "orange milk cap".
is 3 – wide, convex, eventually becoming shallowly depressed in the center. The margin of the cap is curved inward then arched, with short translucent striations (grooves) at maturity. The cap surface is slimy to sticky, smooth, not zonate. It is scarlet
when young, but becomes orange to yellowish-orange and duller when older. The attachment of the gills to the stem
is adnate
(squarely attached) to decurrent
(running down the length of the stem); the gills are moderately broad, with spacing close to subdistant (with visible spaces between the gills). They are whitish or colored similar to the cap but paler. The stem is 4 – long, 5 – thick, and thicker near the base. The smooth stem surface can be either moist or dry depending on the moisture in the environment. It is hollow, fragile, and colored like the cap. The flesh
is thin, fragile, pale pinkish-buff to dull orangish-buff. The mushroom's odor is not distinctive, and the taste slowly becomes acrid. The latex
is white, and does not change color with continued exposure to air. It does not stain the tissues, and tastes acrid. The spore print
is white. The edibility
of the fruit bodies is unknown, and consumption is not recommended.
s are 7.5–9 by 6.5–7.5 µm
, with an ellipsoid shape. Their surfaces are ornamented with warts and short ridges that do not form a reticulum (a network of raised net-like ridges on the surface), with ridges up to 1.0 µm high. The spores are hyaline
(translucent), and amyloid
—they absorb iodine
when stained with Melzer's reagent
. The basidia (spore-bearing cells) are four-spored, and measure 42 by 9 µm. The cap cuticle
is a modified ixotrichoderm, meaning that the hypha
e are embedded in a slimy or gelatinous layer.
-tawny
to ochraceous-buff cap and stem, flesh that tastes slightly bitter before slowly turning acrid, white latex that tastes mild to somewhat astringent, and a buff-colored spore print. Lactarius luculentus var. laetus is another lookalike, but may be distinguished by a brownish-orange to grayish-orange stem, and mild-tasting latex. Lactarus substriatus has white latex that slowly changes color to yellow, and Lactarius subviscidus has similar overall coloring but white latex that changes to yellow. The Californian species L. cocosiolens has a sticky orange-brown to caramel-colored cap. It has a mild taste, abundant latex, and as its specific epithet suggests, smells like coconut when it is dry.
, forming mutualistic associations with trees. The fungus and the plant forms structures called ectomycorrhizae, a specialized sheath of hypha
e on the surface of the root from which hyphae extend into the soil and into the outer cortical
cells of the root. The fruit bodies of L. subflammeus grow scattered to grouped under conifers or in mixed conifer-hardwood forests near pine
and spruce
, from August to December. The fungus is widely distributed in the Pacific Northwest
, where it is very common in conifer forests. The habitat of the type location was coastal sand dunes under pine. States from which the fungus has been collected include Washington, Idaho
, Oregon
, California
, and Colorado
. The mushroom's range extends north into Canada, where it has been found near Victoria, British Columbia
in coastal forests dominated by Douglas-fir
(Pseudotsuga menziesii).
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 Russulaceae
Russulaceae
The Russulaceae are a family of fungi in the order Russulales. According to a 2008 estimate, the family contains 1243 species. Its species typically have fruit bodies with friable, chalk-like stalks, that break with a distinct crack, somewhat like a carrot but with porous flesh...
family. It is found in western North America in the late summer and fall and is especially common in the Pacific Northwest
Pacific Northwest
The Pacific Northwest is a region in northwestern North America, bounded by the Pacific Ocean to the west and, loosely, by the Rocky Mountains on the east. Definitions of the region vary and there is no commonly agreed upon boundary, even among Pacific Northwesterners. A common concept of the...
, where it grows on the ground near conifers like pine
Pine
Pines are trees in the genus Pinus ,in the family Pinaceae. They make up the monotypic subfamily Pinoideae. There are about 115 species of pine, although different authorities accept between 105 and 125 species.-Etymology:...
and 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...
. The brightly colored 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...
, which are slimy or sticky, have scarlet 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...
when young that soon fade to brilliant orange. 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...
—typically longer than the width of the cap—is also bright orange but the gills are whitish. The mushroom secretes a whitish latex
Latex
Latex is the stable dispersion of polymer microparticles in an aqueous medium. Latexes may be natural or synthetic.Latex as found in nature is a milky fluid found in 10% of all flowering plants . It is a complex emulsion consisting of proteins, alkaloids, starches, sugars, oils, tannins, resins,...
when it is cut or injured.
Taxonomy
The species was first described by Lexemuel Ray HeslerLexemuel Ray Hesler
-External links:* Finding Aid for the Lexemuel Ray Hesler Collection, 1899-1982...
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 1979 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...
of North American species of the genus 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...
, based on specimens collected from Pacific City, Oregon
Pacific City, Oregon
Pacific City is a census-designated place and unincorporated community in Tillamook County, Oregon, United States. The population was 1,027 at the 2000 census...
. Prior to this description, the species had frequently been confused in the literature with L. aurantiacus. The specific epithet subflammeus means "almost flame color". It is classified in the section
Section (botany)
In botany, a section is a taxonomic rank below the genus, but above the species. The subgenus, if present, is higher than the section, and the rank of series, if present, is below the section. Sections are typically used to help organise very large genera, which may have hundreds of species...
Russularia of the subgenus
Subgenus
In biology, a subgenus is a taxonomic rank directly below genus.In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the Tiger Cowry of the Indo-Pacific, Cypraea tigris Linnaeus, which...
Russularia of Lactarius. Species in this subgenus have small to medium-sized and fragile fruit bodies.
Lactarius subflammeus 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 "orange milk cap".
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...
is 3 – wide, convex, eventually becoming shallowly depressed in the center. The margin of the cap is curved inward then arched, with short translucent striations (grooves) at maturity. The cap surface is slimy to sticky, smooth, not zonate. It is scarlet
Scarlet (color)
Scarlet is a bright red color with a hue that is somewhat toward the orange. It is redder than vermilion. It is a pure chroma on the color wheel one-fourth of the way between red and orange. Scarlet is sometimes used as the color of flame...
when young, but becomes orange to yellowish-orange and duller when older. The attachment of the gills to 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 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....
(squarely attached) to 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...
(running down the length of the stem); the gills are moderately broad, with spacing close to subdistant (with visible spaces between the gills). They are whitish or colored similar to the cap but paler. The stem is 4 – long, 5 – thick, and thicker near the base. The smooth stem surface can be either moist or dry depending on the moisture in the environment. It is hollow, fragile, and colored like the cap. 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, fragile, pale pinkish-buff to dull orangish-buff. The mushroom's odor is not distinctive, and the taste slowly becomes acrid. The latex
Latex
Latex is the stable dispersion of polymer microparticles in an aqueous medium. Latexes may be natural or synthetic.Latex as found in nature is a milky fluid found in 10% of all flowering plants . It is a complex emulsion consisting of proteins, alkaloids, starches, sugars, oils, tannins, resins,...
is white, and does not change color with continued exposure to air. It does not stain the tissues, and tastes acrid. 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. 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 fruit bodies is unknown, and consumption is not recommended.
Microscopic characteristics
The sporeSpore
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 7.5–9 by 6.5–7.5 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...
, with an ellipsoid shape. Their surfaces are ornamented with warts and short ridges that do not form a reticulum (a network of raised net-like ridges on the surface), with ridges up to 1.0 µm high. The spores are hyaline
Hyaline
The term hyaline denotes a substance with a glass-like appearance.-Histopathology:In histopathological medical usage, a hyaline substance appears glassy and pink after being stained with haematoxylin and eosin — usually it is an acellular, proteinaceous material...
(translucent), 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...
—they absorb iodine
Iodine
Iodine is a chemical element with the symbol I and atomic number 53. The name is pronounced , , or . The name is from the , meaning violet or purple, due to the color of elemental iodine vapor....
when stained 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:...
. The basidia (spore-bearing cells) are four-spored, and measure 42 by 9 µm. 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 modified ixotrichoderm, meaning that 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 are embedded in a slimy or gelatinous layer.
Similar species
Lactarius luculentus var. luculentus is similar in appearance, but it has an ochraceousOchre
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...
-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 ochraceous-buff cap and stem, flesh that tastes slightly bitter before slowly turning acrid, white latex that tastes mild to somewhat astringent, and a buff-colored spore print. Lactarius luculentus var. laetus is another lookalike, but may be distinguished by a brownish-orange to grayish-orange stem, and mild-tasting latex. Lactarus substriatus has white latex that slowly changes color to yellow, and Lactarius subviscidus has similar overall coloring but white latex that changes to yellow. The Californian species L. cocosiolens has a sticky orange-brown to caramel-colored cap. It has a mild taste, abundant latex, and as its specific epithet suggests, smells like coconut when it is dry.
Ecology, habitat and distribution
Like all species in the genus Lactarius, L. subflammeus is mycorrhizalMycorrhiza
A mycorrhiza is a symbiotic association between a fungus and the roots of a vascular plant....
, forming mutualistic associations with trees. The fungus and the plant forms structures called ectomycorrhizae, a specialized sheath of 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 on the surface of the root from which hyphae extend into the soil and into the outer cortical
Cortex (botany)
In botany, the cortex is the outer layer of the stem or root of a plant, bounded on the outside by the epidermis and on the inside by the endodermis. It is composed mostly of undifferentiated cells, usually large thin-walled parenchyma cells of the ground tissue system. The outer cortical cells...
cells of the root. The fruit bodies of L. subflammeus grow scattered to grouped under conifers or in mixed conifer-hardwood forests near pine
Pine
Pines are trees in the genus Pinus ,in the family Pinaceae. They make up the monotypic subfamily Pinoideae. There are about 115 species of pine, although different authorities accept between 105 and 125 species.-Etymology:...
and 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...
, from August to December. The fungus is widely distributed 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...
, where it is very common in conifer forests. The habitat of the type location was coastal sand dunes under pine. States from which the fungus has been collected include Washington, Idaho
Idaho
Idaho is a state in the Rocky Mountain area of the United States. The state's largest city and capital is Boise. Residents are called "Idahoans". Idaho was admitted to the Union on July 3, 1890, as the 43rd state....
, Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
, 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...
, and Colorado
Colorado
Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...
. The mushroom's range extends north into Canada, where it has been found near Victoria, British Columbia
Victoria, British Columbia
Victoria is the capital city of British Columbia, Canada and is located on the southern tip of Vancouver Island off Canada's Pacific coast. The city has a population of about 78,000 within the metropolitan area of Greater Victoria, which has a population of 360,063, the 15th most populous Canadian...
in coastal forests dominated by 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...
(Pseudotsuga menziesii).