''Boletus barrowsii'', also known in English as the white king bolete after its pale colored

cap A cap is a flat headgear, usually with a visor. Caps have crowns that fit very close to the head. They made their first appearance as early as 3200 BC. Caps typically have a visor, or no brim at all. They are popular in casual and informal se ...

, is an edible and highly regarded

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 fr ...

in the genus ''

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 ...

'' that inhabits western North America. Found under

ponderosa pine ''Pinus ponderosa'', commonly known as the ponderosa pine, bull pine, blackjack pine, western yellow-pine, or filipinus pine is a very large pine tree species of variable habitat native to mountainous regions of western North America. It is the ...

and

live oak Live oak or evergreen oak is any of a number of oaks in several different sections of the genus ''Quercus'' that share the characteristic of evergreen foliage. These oaks are not more closely related to each other than they are to other oaks. ...

in autumn, it was considered a color variant of the similarly edible '' B. edulis'' for many years.

Taxonomy and naming

It was officially described by American mycologists

Harry D. 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 St ...

and

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, Wi ...

in 1976 from a specimen collected near

Jacob Lake, Arizona Jacob Lake is a small unincorporated community on the Kaibab Plateau in Coconino County, Arizona, United States, at the junction of U.S. Route 89A and State Route 67. Named after the Mormon explorer Jacob Hamblin, the town is known as the "G ...

, on August 21, 1971, by amateur mycologist Charles "Chuck" Barrows, who had studied the mushroom in New Mexico. It was previously held to be a white colour form of ''

Boletus edulis ''Boletus edulis'' (English: cep, penny bun, porcino or porcini) is a basidiomycete fungus, and the type species of the genus ''Boletus''. Widely distributed in the Northern Hemisphere across Europe, Asia, and North America, it does not occu ...

''. A 2010 molecular study found that ''B. barrowsii'' was sister to a lineage that gave rise to the species '' B. quercophilus'' of Costa Rica and '' B. nobilissimus'' of eastern North America.

Description

The

is 6–25 cm (2–10 in) in diameter, initially convex in shape before flattening, with a smooth or slightly tomentose surface, and gray-white, white or

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 w ...

color. The thick

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, but ...

is white and does not turn blue when bruised. The pores are initially whitish, later yellow. The

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 pinkish-tan spore print. A 3.5-centimeter ...

is olive brown, the

spores In biology, a spore is a unit of sexual 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 plants, algae, ...

are elliptical to spindle-shaped and 13–15 x 4–5

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

in dimensions. The stout stipe is white with a brown reticulated pattern, and may be 6–20 cm (–8 in) high with an apical diameter of 2–6 cm (1–2 in). Like ''B. edulis'', it is often found eaten by

maggot A maggot is the larva of a fly (order Diptera); it is applied in particular to the larvae of Brachycera flies, such as houseflies, cheese flies, and blowflies, rather than larvae of the Nematocera, such as mosquitoes and crane flies. En ...

s. It has a strong odor while drying.

Distribution and habitat

The white king bolete is

ectomycorrhiza An ectomycorrhiza (from Greek ἐκτός ', "outside", μύκης ', "fungus", and ῥίζα ', "root"; pl. ectomycorrhizas or ectomycorrhizae, abbreviated EcM) is a form of symbiotic relationship that occurs between a fungal symbiont, or my ...

l, found under

(''Pinus ponderosa'') inland, and coast live oak (''Quercus agrifolia'') closer to the west coast. Fruit bodies appear after rain, and will be more abundant if this occurs in early autumn rather than later in the year through to winter. It is abundant in the warmer parts of its range, namely

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

and

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe, New Mexico, Santa Fe , LargestCity = Albuquerque, New Mexico, Albuquerque , LargestMetro = Albuquerque metropolitan area, Tiguex , Offi ...

, but also occurs in

Colorado Colorado (, other variants) is a state in the Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of the ...

, west into

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

and north to

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, for ...

. It has been recorded from the San Marcos Foothills in

Santa Barbara County Santa Barbara County, California, officially the County of Santa Barbara, is located in Southern California. As of the 2020 census, the population was 448,229. The county seat is Santa Barbara, and the largest city is Santa Maria. Santa Barba ...

Edibility

The species is edible and highly regarded in New Mexico, Arizona, and Colorado, and was eaten for many years while assumed to be a form of ''B. edulis''.

Similar species

In addition to ''B. edulis'', the species could also be confused with the similarly pale-capped ''

Boletus satanas ''Rubroboletus satanas'', commonly known as Satan's bolete or the Devil's bolete, is a basidiomycete fungus of the bolete family (Boletaceae) and one of its most infamous members. It was known as ''Boletus satanas'' before its transfer to the ...

'', though the flesh of the latter stains blue when cut or bruised, and it has a reddish stem and pores. The latter species is

poisonous Poison is a chemical substance that has a detrimental effect to life. The term is used in a wide range of scientific fields and industries, where it is often specifically defined. It may also be applied colloquially or figuratively, with a broa ...

when raw.

References