''Lactarius repraesentaneus'', commonly known as the northern bearded milkcap, the northern milkcap, or the purple-staining bearded milkcap, is a species of
fungus
A fungus ( : fungi or funguses) is any member of the 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, separately from th ...
in the family
Russulaceae. It has a northerly distribution, and is found in
temperate
In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout t ...
regions of North America and Europe, associated with
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 (taiga) regions of the Earth. ''Picea'' is the sole genus in the subfami ...
trees. Distinguishing features of its
fruit body
In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the Ovary (plants), ovary after flowering plant, flowering.
Fruits are the means by which flowering plants (also known as angiosperms) disseminate their ...
include the large orange-yellow
cap up to wide, cream to pale yellow
gills, and a yellow coarsely-pitted
stem
Stem or STEM may refer to:
Plant structures
* Plant stem, a plant's aboveground axis, made of vascular tissue, off which leaves and flowers hang
* Stipe (botany), a stalk to support some other structure
* Stipe (mycology), the stem of a mushro ...
that is up to long and thick. Cut fruit bodies ooze a white
latex
Latex is an emulsion (stable dispersion) of polymer microparticles in water. Latexes are found in nature, but synthetic latexes are common as well.
In nature, latex is found as a milky fluid found in 10% of all flowering plants (angiosperms ...
that will stain mushroom tissue
lilac
''Syringa'' is a genus of 12 currently recognized species of flowering plant, flowering woody plants in the olive family or Oleaceae called lilacs. These lilacs are native to woodland and scrub from southeastern Europe to eastern Asia, and wid ...
to purple. Several chemicals have been isolated and identified from the fruit bodies that can modify the growth of plants, and the mushroom also has
antibiotic
An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of ...
activity against ''
Staphylococcus aureus
''Staphylococcus aureus'' is a Gram-positive spherically shaped bacterium, a member of the Bacillota, and is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. It is often positive ...
''. ''L. repraesentaneus'' is
poisonous, and consumption causes stomach aches.
Taxonomy
''Lactarius repraesentaneus'' was first described by German mycologist
Max Britzelmayr
Max Britzelmayr (7 January 1839 – 6 December 1909) was a German mycologist and lichenologist who was a native of Augsburg.
He spent his career as a schoolteacher and ''Kreisschulinspektor'' (school district administrator) in Augsburg. He is k ...
in 1885, based on material collected from
Bavaria
Bavaria ( ; ), officially the Free State of Bavaria (german: Freistaat Bayern, link=no ), is a state in the south-east of Germany. With an area of , Bavaria is the largest German state by land area, comprising roughly a fifth of the total lan ...
.
[ The variety ''Lactarius scrobiculatus'' var. ''repraesentaneus'', proposed by Killermann in 1933,][ is considered a ]synonym
A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...
.Rolf Singer
Rolf Singer (June 23, 1906 – January 18, 1994) was a Germany, German-born mycologist and one of the most important Taxonomy (biology), taxonomists of gilled mushrooms (agarics) in the 20th century.
After receiving his Ph.D. at the University ...
in 1942 defined the subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...
''L. repraesentaneus'' ssp. ''speciosus'' to include fruit bodies with matted fibers ("felt") arranged in concentric rings on the cap (