''Leccinum holopus'', commonly known as the white birch bolete, white bog bolete, or ghost bolete, is a species of

bolete A bolete is a type of mushroom, or fungal fruiting body. It can be identified thanks to a unique cap. On the underside of the cap there is usually a spongy surface with pores, instead of the gills typical of mushrooms. A similar pore surface i ...

fungus in the family

Boletaceae The Boletaceae are a Family (biology), family of mushroom-forming fungi, primarily characterised by small pores on the spore-bearing hymenium, hymenial surface (at the underside of the mushroom), instead of Lamella (mycology), gills as are found ...

found in northern Asia, Europe, and northeastern North America. It associates with

birch A birch is a thin-leaved deciduous hardwood tree of the genus ''Betula'' (), in the family Betulaceae, which also includes alders, hazels, and hornbeams. It is closely related to the beech- oak family Fagaceae. The genus ''Betula'' contains 3 ...

trees and is typically found in

bog A bog or bogland is a wetland that accumulates peat as a deposit of dead plant materials often mosses, typically sphagnum moss. It is one of the four main types of wetlands. Other names for bogs include mire, mosses, quagmire, and musk ...

gy or swampy areas, often growing among

sphagnum moss ''Sphagnum'' is a genus of approximately 380 accepted species of mosses, commonly known as sphagnum moss, also bog moss and quacker moss (although that term is also sometimes used for peat). Accumulations of ''Sphagnum'' can store water, since ...

. Fruitbodies (

mushroom A mushroom or toadstool is the fleshy, spore-bearing Sporocarp (fungi), fruiting body of a fungus, typically produced above ground on soil or another food source. ''Toadstool'' generally refers to a poisonous mushroom. The standard for the n ...

s) of ''L. holopus'' have convex

caps Caps are flat headgear. Caps or CAPS may also refer to: Science and technology Computing * CESG Assisted Products Service, provided by the U.K. Government Communications Headquarters * Composite Application Platform Suite, by Java Caps, a Java ...

measuring up to in diameter. Often pure white—especially in young fruitbodies—the caps sometimes become flushed with

buff Buff or BUFF may refer to: People * Buff (surname), a list of people * Buff (nickname), a list of people * Johnny Buff, ring name of American world champion boxer John Lisky (1888–1955) * Buff Bagwell, a ring name of American professional wr ...

or brownish tints. The whitish surface of the stipe is covered with small, stiff, projecting scales (scabers) that become tan or darker in age. Some

varieties Variety may refer to: Arts and entertainment Entertainment formats * Variety (radio) * Variety show, in theater and television Films * ''Variety'' (1925 film), a German silent film directed by Ewald Andre Dupont * ''Variety'' (1935 film), ...

of ''Leccinum holopus'' have been described that vary in cap color or staining reaction, but

DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

evidence suggests that most are the same

taxon In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...

. Although the fruitbodies are

edible An edible item is any item that is safe for humans to eat. "Edible" is differentiated from " eatable" because it does not indicate how an item tastes, only whether it is fit to be eaten. Nonpoisonous items found in nature – such as some mushroo ...

, opinions vary as to their culinary desirability.

Taxonomy

Initially named as a species of ''

Boletus ''Boletus'' is a genus of mushroom-producing fungi, comprising over 100 species. The genus ''Boletus'' was originally broadly defined and described by Carl Linnaeus in 1753, essentially containing all fungi with hymenial pores instead of gills. ...

'' by German mycologist Friedrich Rostkovius in 1844, the fungus was later transferred to ''

Leccinum ''Leccinum'' is a genus of fungi in the family Boletaceae. It was the name given first to a series of fungi within the genus '' Boletus'', then erected as a new genus last century. Their main distinguishing feature is the small, rigid projection ...

'' by

Roy Watling Roy Watling (born 1938) is a Scottish mycologist who has made significant contributions to the study of fungi both in the identification of new species and correct taxonomic placement, as well as in fungal ecology. Biography Watling was the Hea ...

in 1960.

Synonyms A synonym is a word, morpheme, or phrase that means precisely 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 a ...

resulting from transfer to different genera include: ''Krombholzia holopoda'' and ''K. holopus'' (both published by

Albert Pilát Albert Pilát (November 2, 1903 – May 29, 1974) was a Czech botany, botanist and mycology, mycologist. He studied at the Faculty of Science at Charles University, under the guidance of Professor Josef Velenovský. In 1930, he joined the Nationa ...

in 1951); ''Krombholziella holopus'' (Josef Šutara, 1989); ''Trachypus holopus'' (

Paul Konrad Paul Konrad (1 April 1877 in Le Locle – 19 December 1948 in Neuchâtel) was a Swiss geometrician and amateur mycologist. From 1902 he was an employee of the Compagnie des Tramways de Neuchâtel, of which, he served as a director from 1938 ...

and

André Maublanc André Pierre Jules Maublanc (24 July 1880, in Nantes – 30 April 1958, in Paris) was a French mycologist and plant pathologist. Beginning in 1902, he worked as a préparateur at the Station de Pathologie végétale in Paris. In 1912, he traveled ...

, 1952), and ''Trachypus scaber'' f. ''holopus'' (

Henri Romagnesi Henri Charles Louis Romagnesi (7 February 1912 – 18 January 1999) was a French mycologist who was notable for a thorough review and monograph of the agaric genus ''Entoloma'' (or ''Rhodophyllus'' as it was known in the early 20th century), as w ...

, 1939). Other synonyms, according to

Index Fungorum ''Index Fungorum'' is an international project to index all formal names (scientific names) in the fungus kingdom. As of 2015, the project is based at the Royal Botanic Gardens, Kew, one of three partners along with Landcare Research and th ...

, include ''Leccinum olivaceosum'', described from France in 1994, and ''Leccinum aerugineum'' (1991). ''Leccinum holopus'' is

classified Classified may refer to: General *Classified information, material that a government body deems to be sensitive *Classified advertising or "classifieds" Music *Classified (rapper) (born 1977), Canadian rapper * The Classified, a 1980s American ro ...

section Section, Sectioning, or Sectioned may refer to: Arts, entertainment and media * Section (music), a complete, but not independent, musical idea * Section (typography), a subdivision, especially of a chapter, in books and documents ** Section sig ...

''Scabra'' of genus ''Leccinum'', a grouping that includes

Northern Hemisphere The Northern Hemisphere is the half of Earth that is north of the equator. For other planets in the Solar System, north is defined by humans as being in the same celestial sphere, celestial hemisphere relative to the invariable plane of the Solar ...

species associating exclusively with birch. The

specific epithet In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

''holopus'' is

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

for "with perfect stalk".

Common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often con ...

s given to the fungus include white birch bolete, white bog bolete, and ghost bolete. Several subtaxa of ''Leccinum holopus'' have been described. In

form Form is the shape, visual appearance, or configuration of an object. In a wider sense, the form is the way something happens. Form may also refer to: *Form (document), a document (printed or electronic) with spaces in which to write or enter dat ...

''aerugineum'', described by Josef Šutara in 2009, the flesh discolors green after injury. The

variety Variety may refer to: Arts and entertainment Entertainment formats * Variety (radio) * Variety show, in theater and television Films * ''Variety'' (1925 film), a German silent film directed by Ewald Andre Dupont * ''Variety'' (1935 film), ...

''americanum'', described by

Alexander H. Smith Alexander Hanchett Smith (December 12, 1904 – December 12, 1986) was an American mycologist known for his extensive contributions to the taxonomy and phylogeny of the higher fungi, especially the agarics. Early life Smith, born in Crandon, Wis ...

and

Harry Delbert Thiers Harry Delbert Thiers (January 22, 1919, in Fort McKavett, Texas – August 8, 2000, in Ohio) was an American mycologist who studied and named many fungi native to North America, particularly California. Thiers taught mycology at San Francisco ...

in 1971 from collections made in

Michigan Michigan ( ) is a peninsular U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest, Upper Midwestern United States. It shares water and land boundaries with Minnesota to the northwest, Wisconsin to the west, ...

, injured flesh stains reddish. Lannoy & Estadès described ''Leccinum nucatum'' in 1993, a taxon that was later (2007) published as variety ''nucatum'' of ''L. holopus''; no

molecular A molecule is a group of two or more atoms that are held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions that satisfy this criterion. In quantum physics, organic chemistry, ...

evidence was found supporting the existence of this as a distinct taxon, and it is therefore placed into synonymy with ''L. holopus''. ''Leccinum holopus'' var. ''majus'', described by

Rolf Singer Rolf Singer (June 23, 1906 – January 18, 1994) was a German mycologist and Taxonomy (biology), taxonomist of gilled mushrooms (agarics). He wrote the book "The Agaricales in Modern Taxonomy (biology), Taxonomy". He fled to various countries d ...

in 1966 (originally published by Singer as ''Krombholzia scabra'' f. ''majus''), is another historical variety without independent

taxonomic 280px, Generalized scheme of taxonomy Taxonomy is a practice and science concerned with classification or categorization. Typically, there are two parts to it: the development of an underlying scheme of classes (a taxonomy) and the allocation ...

significance.

Description

Fruitbodies of ''Leccinum holopus'' have convex to flattened

measuring in diameter, with a narrow band of sterile tissue surrounding the margin. The caps are initially whitish, but can develop gray,

, tan, or pinkish tints during maturity; the color may also darken and become greenish with age. The cap surface is initially covered with very fine hairs, but later becomes more or less smooth, often with a sticky texture in age or in moist conditions. The

flesh Flesh is any aggregation of soft tissues of an organism. Various multicellular organisms have soft tissues that may be called "flesh". In mammals, including humans, ''flesh'' encompasses muscles, fats and other loose connective tissues, ...

is white and lacks any distinct odor or taste; it can have either little or no bruising color reaction with injury, or may become light pink in variety ''americanum''. On the cap underside is a porous surface comprising pores numbering 2 to 3 per millimeter, each of which is the end of a tube that extends to deep. The color of the pore surface ranges from whitish to grayish to dingy brown, and has little color reaction to injury, although it may discolor yellowish or brownish. There is a depression where the pores meet the stipe. The stipe measures long by wide. Its whitish surface is covered with scabers that darken in age to tan or darker. The stipe base often stains bluish. ''Leccinum holopus'' produces a brown

spore print 300px, Making a spore print of the mushroom ''Volvariella volvacea'' shown in composite: (photo lower half) mushroom cap laid on white and dark paper; (photo upper half) cap removed after 24 hours showing warm orange ("tussock") color spore print. ...

Spores In biology, a spore is a unit of sexual (in fungi) or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plant ...

are somewhat fusoid (spindle-shaped) and measure 14–20 by 5–6.5

μm The micrometre (Commonwealth English as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American English), also commonly known by the non-SI term micron, is a unit of length in the International System ...

. The

basidia A basidium (: basidia) is a microscopic spore-producing structure found on the hymenophore of reproductive bodies of basidiomycete fungi. The presence of basidia is one of the main characteristic features of the group. These bodies are also ...

(spore-bearing cells) are four-spored and measure 28.5–36.5 by 11.5–12.5 μm.

Cystidia A cystidium (: cystidia) is a relatively large cell found on the sporocarp of a basidiomycete (for example, on the surface of a mushroom gill), often between clusters of basidia. Since cystidia have highly varied and distinct shapes that are o ...

on the pores are flask-shaped (lageniform) to fusiform, and 39.0–45.5 by 7.5–9.0 μm, while those of the stipe (caulocystidia) are fusiform, club-shaped, or cylindrical, measuring 39.0–54.5 x 9.1–13.5 μm. There are no

clamp connection A clamp connection is a hook-like structure formed by growing hyphal cells of certain fungi. It is a characteristic feature of basidiomycete fungi. It is created to ensure that each cell, or segment of hypha separated by septa (cross walls), rece ...

s present in the

hypha A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one o ...

e of ''L. holopus''. The

cap cuticle The pileipellis is the uppermost layer of hyphae in the pileus of a fungal fruit body. It covers the trama, the fleshy tissue of the fruit body. The pileipellis is more or less synonymous with the cuticle, but the cuticle generally describes th ...

is arranged in the form of a cutis—with hyphae that run parallel to the cap surface. Several

chemical tests A chemical substance is a unique form of matter with constant chemical composition and characteristic properties. Chemical substances may take the form of a single element or chemical compounds. If two or more chemical substances can be combine ...

can be used to help verify an identification of ''L. holopus''. A drop of

ammonium hydroxide Ammonia solution, also known as ammonia water, ammonium hydroxide, ammoniacal liquor, ammonia liquor, aqua ammonia, aqueous ammonia, or (inaccurately) ammonia, is a solution of ammonia in water. It can be denoted by the symbols NH3(aq). Although ...

solution turns the cap cuticle a pinkish color, but has no reaction with the flesh. A drop of dilute

potassium hydroxide Potassium hydroxide is an inorganic compound with the formula K OH, and is commonly called caustic potash. Along with sodium hydroxide (NaOH), KOH is a prototypical strong base. It has many industrial and niche applications, most of which utili ...

(KOH) has no reaction on the cap surface, and either no reaction or a brownish reaction with the flesh. Application of

iron(II) sulfate Iron(II) sulfate or ferrous sulfate (British English: sulphate instead of sulfate) denotes a range of salts with the formula Fe SO4·''x''H2O. These compounds exist most commonly as the heptahydrate (''x'' = 7), but several values for ...

solution does not have a reaction on the cap surface, and either no reaction to slightly olive coloration on the flesh.

Similar species

'' Leccinellum albellum'' is similar in appearance to ''L. holopus'', but grows in association with

oak An oak is a hardwood tree or shrub in the genus ''Quercus'' of the beech family. They have spirally arranged leaves, often with lobed edges, and a nut called an acorn, borne within a cup. The genus is widely distributed in the Northern Hemisp ...

and has a more southerly distribution. '' L. scabrum'' is a widely distributed lookalike that can be distinguished from ''L. holopus'' by its larger size and generally darker colors.

Edibility

Although commonly considered

, opinions vary on the culinary appeal of ''Leccinum holopus'' fruitbodies. Michael Kuo, writing in ''100 Edible Mushrooms'', considers it a good edible; Peter Roberts and Shelley Evans in ''The Book of Fungi'' say "it is edible, but is said to be tasteless and pappy, so is not recommended." Fruitbodies are optimally harvested when they are young, before the flesh becomes too spongy, and before insect larvae establish themselves. Minimal cleaning is required in the field. The mushroom has a mild, somewhat sweet flavor that is enhanced after brief sauteeing. Drying the mushrooms enhances the flavor, but diminishes the sweetness of fresh mushrooms.

Habitat and distribution

''Leccinum holopus'' is a

mycorrhiza A mycorrhiza (; , mycorrhiza, or mycorrhizas) is a symbiotic association between a fungus and a plant. The term mycorrhiza refers to the role of the fungus in the plant's rhizosphere, the plant root system and its surroundings. Mycorrhizae play ...

l species. It fruits on the ground (often among ''

Sphagnum ''Sphagnum'' is a genus of approximately 380 accepted species of mosses, commonly known as sphagnum moss, also bog moss and quacker moss (although that term is also sometimes used for peat). Accumulations of ''Sphagnum'' can store water, since ...

'' moss), singly to scattered in wet areas like

cedar Cedar may refer to: Trees and plants *''Cedrus'', common English name cedar, an Old-World genus of coniferous trees in the plant family Pinaceae * Cedar (plant), a list of trees and plants known as cedar Places United States * Cedar, Arizona ...

swamps,

bogs A bog or bogland is a wetland that accumulates peat as a deposit of dead plant materials often mosses, typically sphagnum moss. It is one of the four main Wetland#Types, types of wetlands. Other names for bogs include mire, mosses, quagm ...

, or soggy forests. Like most ''Leccinum'' species, the fungus is highly host-specific and associates with

(''Betula''). In North America, the range of ''Leccinum holopus'' extends from eastern Canada to

New York New York most commonly refers to: * New York (state), a state in the northeastern United States * New York City, the most populous city in the United States, located in the state of New York New York may also refer to: Places United Kingdom * ...

, extending west to the northern

Rocky Mountain The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of Western Canada, to New Mexico in ...

s, roughly coinciding with the distribution of the

paper birch Paper is a thin sheet material produced by mechanically or chemically processing cellulose fibres derived from wood, rags, grasses, herbivore dung, or other vegetable sources in water. Once the water is drained through a fine mesh leaving ...

(''Betula papyrifera''). In this range, it is common and fruits from August to October. ''L. holopus'' var. ''americanum'' is known only from North America. The fungus is rare in southern Europe, but more common in the ''Sphagnum'' swamps in the north. In Asia, it has been recorded from Taiwan and

Qinghai Qinghai is an inland Provinces of China, province in Northwestern China. It is the largest provinces of China, province of China (excluding autonomous regions) by area and has the third smallest population. Its capital and largest city is Xin ...

(China). Fruitbodies of ''L. holopus'' are a source of food for

fly Flies are insects of the order Diptera, the name being derived from the Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advanced ...

species such as '' Pegomya winthemi'' (family

Anthomyiidae The Anthomyiidae are a large and diverse family (biology), family of Muscoidea fly, flies. Most look rather like small houseflies. Most species are drab grey to black. Many ''Pegomya'' are yellow, and some members of the genus, genera ''Ant ...

) and '' Megaelia pygmaeoides'' (family

Phoridae The Phoridae are a family of small, hump-backed flies resembling fruit flies. Phorid flies can often be identified by their escape habit of running rapidly across a surface rather than taking flight. This behaviour is a source of one of their al ...

References

{{Taxonbar, from=Q1328979 Edible fungi Fungi described in 1844 Fungi of Asia Fungi of Europe Fungi of North America

holopus ''Holopus'' is a genus of echinoderms belonging to the family Holopodidae. The species of this genus are found in Central America and the Pacific Ocean (near Australia). Species: *''Holopus alidis'' *''Holopus mikihe'' *''Holopus rangii ' ...