Lactarius fumosus, commonly known as the smoky milkcap, is a 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.

Taxonomy

The species was first described 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 1872. "Lactarius fumosus" var. fumosus is considered a synonym

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...

.

Lactarius fumosus is the type species

Type species

In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...

 of the section Fumosi 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...

 Plinthogalus 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...

.

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 "smoky milkcap".

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 3 – wide, broadly convex to nearly plane, sometimes shallowly depressed. The margin (cap edge) is irregular, often wavy, and lobed or ribbed. The cap surface is dry, unpolished, azonate, usually becoming somewhat wrinkled with age, pale dingy yellow-brown to whitish overall, with a smoky tinge, sometimes with tawny olive, pinkish buff, or dull brown areas. The gills are attached to subdecurrent (running slightly down the length of the stem), narrow, crowded together, whitish, becoming dingy yellow-buff, staining reddish when bruised. The stem is 4 – long, 6 – thick, nearly equal, dry, dull, stuffed, colored like the cap, whitish towards the base, staining reddish, but more slowly than the gills. 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 pale white, staining reddish-salmon when cut. Its odor is not distinctive, but the taste is variable: quickly acrid then mild then slowly staining acrid, or very slowly faintly 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 on exposure, unchanging, staining tissues reddish. 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 pinkish-buff. 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...

 is unknown.

Microscopic characters

The spores are 6–8 by 6–8 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...

, spherical or nearly so, ornamented with ridges that form a partial reticulum, prominences up to 1.5 µm high, 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), 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 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 palisade of cylindrical to club-shaped cells.

Similar species

Lactarius musciola has darker colors, and its gills do not stain reddish where bruised. Lactarius fuliginosus

Lactarius fuliginosus

Lactarius fuliginosus, commonly known as the sooty milkcap, is a species of fungus in the Russulaceae family....

differs in having broad subdistant gills.

Habitat and distribution

The fruit bodies of L. fumosus grow solitary, scattered, or in groups on the ground in woods from July-October. The fungus is widely distributed in eastern North America, and has also been reported from western Canada. Its frequency of occurrence is described as occasional. Its range extends south to northwestern Mexico, where it is found associated with Liquidambar, Magnolia

Magnolia

Magnolia is a large genus of about 210 flowering plant species in the subfamily Magnolioideae of the family Magnoliaceae. It is named after French botanist Pierre Magnol....

, Acer, and Quercus species.

Bioactive compounds

Extracts of the fruit bodies are toxic to the corn earworm, Heliothis zea and the large milkweed bug, Oncopeltus fasciatus

Oncopeltus fasciatus

The milkweed bug, Oncopeltus fasciatus, is a medium–sized hemipteran of the family Lygaeidae. It feeds mainly on grains, particularly those of the milkweed. Like all hemiptera, it feeds through a long mouthpart known as a rostrum. O...

. The insecticidal

Insecticide

An insecticide is a pesticide used against insects. They include ovicides and larvicides used against the eggs and larvae of insects respectively. Insecticides are used in agriculture, medicine, industry and the household. The use of insecticides is believed to be one of the major factors behind...

 activity is thought to be caused by compounds called chromenes.