Lactarius deceptivus
Encyclopedia
Lactarius deceptivus, commonly known as the deceiving milkcap, is a common species 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 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 throughout eastern North America on the ground in coniferous forests near hemlock
Conium
Conium is a genus of two species of highly poisonous perennial herbaceous flowering plants in the family Apiaceae, native to Europe and the Mediterranean region as Conium maculatum, and to southern Africa as Conium chaerophylloides....

 or deciduous forests near oak
Oak
An oak is a tree or shrub in the genus Quercus , of which about 600 species exist. "Oak" may also appear in the names of species in related genera, notably Lithocarpus...

, and in oak-dominated forests of Costa Rica
Costa Rica
Costa Rica , officially the Republic of Costa Rica is a multilingual, multiethnic and multicultural country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west and the Caribbean Sea to the east....

. It produces large 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 with funnel-shaped 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...

 reaching up to 25 cm (9.8 in) in diameter, on top of hard white stems
Stipe (mycology)
thumb|150px|right|Diagram of a [[basidiomycete]] stipe with an [[annulus |annulus]] and [[volva |volva]]In mycology a stipe refers to the stem or stalk-like feature supporting the cap of a mushroom. Like all tissues of the mushroom other than the hymenium, the stipe is composed of sterile hyphal...

 that may reach 4 – long and up to 3 cm (1.2 in) thick. The gills are closely spaced together and yellowish-cream in color. When young, the cap is white in all parts, but the depressed center becomes dull brownish in age and breaks up into scales. The edge of the cap has a roll of cottony tissue that collapses as the cap expands. The surface of the stem—especially near the base—has a velvety texture. The mushroom "bleeds" a milky white acrid 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. The fruit bodies are 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 have a bitter taste that can be removed with cooking. Similar 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...

species with which L. deceptivus might be confused include L. pipertatus
Lactarius piperatus
Lactarius piperatus, commonly known as the peppery milk-cap is a semi-edible basidiomycete fungus of the genus Lactarius. Despite being edible, it is not recommended due to its poor taste, though can be used as seasoning when dried. The fruiting body is a creamy-white mushroom which is...

, L. pseudodeceptivus, L. caeruleitinctus, L. arcuatus, L. parvulus, and L. subvellereus.

Taxonomy

The species was first described in the scientific literature by American mycologist Charles Horton Peck
Charles Horton Peck
Charles Horton Peck, born March 30, 1833 in Sand Lake, New York, died 1917 in Albany, New York, was an American mycologist of the 19th and early 20th centuries...

 in 1885. The specific epithet deceptivus 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 "deceptive". The name may allude to the contrasting appearance of young and old fruit bodies. It 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 "deceptive lactarius", the "deceiving lactarius", or the "deceptive milkcap". In the state of Puebla, Mexico
Puebla, Mexico
Puebla, Mexico, may refer to:*Puebla, one of the 32 component federal entities of the United Mexican States*Puebla, Puebla, capital city of that state...

, it is known as oreja de chivo, or "kid ear".

Within 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...

, L. deceptivus is classified in 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...

 Lactifluus, section Albati. Characteristics of species in this section include a white or whitish immature cap that may later turn yellow-brown to cinnamon-color; white to cream-colored latex that typically has an acrid taste; a velvet-textured stem due to a cuticle made of long narrow, thick-walled hairs. Other species in this section include L. vellereus
Lactarius vellereus
Lactarius vellereus, commonly known as the fleecy milk-cap, is a very large fungus in the milk-cap genus Lactarius. It is one of the two most common milk-caps found with beech trees, with the other being L. subdulcis.-Description:...

(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...

), L. subvellereus, and L. caeruleitinctus.

Based on a morphological
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....

 study published in 2005, Lactarius tomentosomarginatus is considered synonymous
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...

 with L. deceptivus. L. tomentosomarginatus, described by Hesler and Smith in their 1979 monograph of North American Lactarius species, was considered by them to be a "satellite species", differing from L. deceptivus on the basis of smaller 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, smaller ornamentations on the surface of the spores, crowded and forked narrow gills, and differences in the micro-structure of 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....

.

Description

The 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...

 is 7.5–25.5 cm (3–10 in) in diameter, initially convex, but becomes funnel-shaped in age. The margin (cap edge) is rolled inwards and cottony when young, concealing the immature gills. The cap surface is dry, smooth and whitish when young, often with yellowish or brownish stains, but becomes coarsely scaly and darkens to dull brownish-ochre with age. The gills have an adnate to decurrent attachment to the stem, close to subdistant, white at first then cream to pale ochre. They are 5 – long and 1 – deep. 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 4 – long, up to 3 cm (1.2 in) thick, nearly equal in width throughout or tapered downward. It is dry, scurfy to nearly smooth and white, staining brown with age. It is initially stuffed (as if filled with cotton), but later becomes hollow. 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 thick and white, and between 3 and 15 mm (0.118110236220472 and 0.590551181102362 in) thick. The latex produced by the mushroom is white, and does not change color upon exposure to air, although it stains the mushroom flesh a yellowish-brown color.

The odor of the flesh and latex may range from indistinct to pungent or turnip-like in age; the taste is strongly acrid—so much that it may have an anesthetizing effect in the throat. In his original description of the species, Peck reported "An experiment of its edible qualities was made without any evil consequences." Thorough cooking removes the bitter taste, but the mushroom is not highly regarded as an edible, and as Hesler and Smith have noted "... but even with this compensating feature some of our acquaintances have found it rather undesirable (and indigestible)." The mushroom is sold at traditional markets in Puebla, Mexico.

Microscopic characteristics

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...

, freshly made, is white to whitish; after drying out the spores in mass are pale yellowish. 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 broadly ellipsoid, 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 measure 9–13 by 7–9 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...

. An apiculus is prominent. The spores are ornamented with warts and spines that do not form a reticulum (a system of raised, net-like ridges) on the surface. The prominences are up to 1.5 µm high, 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...

, meaning 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 46–58 by 7–9 µm. The pleurocystidia (cystidia
Cystidium
A cystidium is a relatively large cell found on the hymenium of a basidiomycete , often between clusters of basidia. Since cystidia have highly varied and distinct shapes that are often unique to a particular species or genus, they are a useful micromorphological characteristic in the...

 found on the face of a gill) are very abundant, roughly club-shaped to ventricose
Ventricose
In mycology, Ventricose is a condition in which the cystidia, lamella or stipe of a mushroom is swollen in the middle....

(swollen in the middle), with apices often tapering; their dimensions are 48–96 x 6–10 µm. The cheilocystidia (cystidia on the edge of the gills) are 40–58 x 5–7 µm, and more or less similar in appearance to the pleurocystidia. 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 made of a layer of somewhat uplifted hyphae. The stem cuticle is a layer of bent-over hyphae bearing thick-walled, filamentous caulocystidia (cystidia on the stem), and it lacks a gelatinous layer.

Similar species

The fungus Lactarius pseudodeceptivus is very similar to L. deceptivus in its external appearance, but it has spore ornamentation that forms a reticulum, and its stem is an ixocutis (a gelatinous layer of hyphae lying parallel to the surface). L. caeruleitinctus is also similar in appearance, but it has a milky-white stem with blue tints that develops more intense blue coloration after handling, and it lacks a cottony, inrolled margin. Other lookalike species include L. arcuatus, which has a much smaller cap and smaller spores, and L. parvulus, which has a small, zonate cap. Russula brevipes
Russula brevipes
Russula brevipes is a species of mushroom commonly known as the short-stemmed russula. It is edible, although its quality is improved once parasitised by the ascomycete fungus Hypomyces lactifluorum, transforming it into an edible known as a lobster mushroom.- Taxonomy :Russula brevipes was...

and R. angustispora are also somewhat similar in appearance, but they do not produce latex when cut or injured. Lactarius subvellereus var. subdistans has more widely spaced gills, and an even cap margin. Lactarius piperatus
Lactarius piperatus
Lactarius piperatus, commonly known as the peppery milk-cap is a semi-edible basidiomycete fungus of the genus Lactarius. Despite being edible, it is not recommended due to its poor taste, though can be used as seasoning when dried. The fruiting body is a creamy-white mushroom which is...

has densely crowded gills, a firm rather than soft and cottony cap margin, and exceedingly acrid latex.

Habitat and distribution

Like all Lactarius species, L. deceptivus is mycorrhizal
Mycorrhiza
A mycorrhiza is a symbiotic association between a fungus and the roots of a vascular plant....

, meaning the fungus forms a mutualistic association with certain trees and shrubs. The subterranean 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...

 of the fungus forms an intimate association with tree roots, enveloping them in a sheath of tissue that allows both organisms to exchange nutrients they would otherwise be unable to obtain. The fruit bodies of the fungus grow solitarily, scattered, or in groups on the ground in conifer or hardwood forests, often under oak
Oak
An oak is a tree or shrub in the genus Quercus , of which about 600 species exist. "Oak" may also appear in the names of species in related genera, notably Lithocarpus...

 (Quercus) or hemlock
Hemlock
The word hemlock may refer to:*Hemlock, several poisonous plants in the Apiaceae family :**Hemlock , two species, one formerly used as a method of execution**Water Hemlock...

 (Tsuga). Smith
Alexander H. Smith
Alexander Hanchett Smith was an American mycologist known for his extensive contributions to the taxonomy and phylogeny of the higher fungi, especially the agarics.-Early life:...

 has noted a preference for bogs and the edges of woodland pools in hardwood forests, and in oak stands that have an understory
Understory
Understory is the term for the area of a forest which grows at the lowest height level below the forest canopy. Plants in the understory consist of a mixture of seedlings and saplings of canopy trees together with understory shrubs and herbs...

 of blueberry bushes (Vaccinium
Vaccinium
Vaccinium is a genus of shrubs or dwarf shrubs in the plant Family Ericaceae. The fruit of many species are eaten by humans and some are of commercial importance, including the cranberry, blueberry, bilberry or whortleberry, lingonberry or cowberry, and huckleberry...

species). It is widely distributed in eastern North America, and has also been reported from southern and western Canada. It is a fairly common species, and fruits from June to October. The mushroom has also been reported from Mexico (in Puebla and in Veracruz
Veracruz
Veracruz, formally Veracruz de Ignacio de la Llave officially Estado Libre y Soberano de Veracruz de Ignacio de la Llave , is one of the 31 states that, along with the Federal District, comprise the 32 federative entities of Mexico. It is divided in 212 municipalities and its capital city is...

) from oak and pine forests, at altitudes slightly over 2000 metres (1.2 mi), and from Costa Rica
Costa Rica
Costa Rica , officially the Republic of Costa Rica is a multilingual, multiethnic and multicultural country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west and the Caribbean Sea to the east....

, where it is abundant in oak forests.
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