Xerocomellus zelleri

Last updated
Xerocomellus zelleri
Xerocomellus zelleri 10114 crop.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Fungi
Division: Basidiomycota
Class: Agaricomycetes
Order: Boletales
Family: Boletaceae
Genus: Xerocomellus
Species:
X. zelleri
Binomial name
Xerocomellus zelleri
(Murrill) Klofac (2011)
Synonyms [1]

Ceriomyces zelleriMurrill (1912)
Boletus zelleri(Murrill) Murrill (1912)
Xerocomus zelleri(Murrill) Snell (1944)
Boletellus zelleri(Murrill) Singer, Snell & E.A.Dick (1960)

Contents

Xerocomellus zelleri
Information icon.svg
Pores icon.pngPores on hymenium
Convex cap icon.svgFlat cap icon.svg Cap is convex or flat
Adnate gills icon2.svg Hymenium is adnate
Bare stipe icon.svg Stipe is bare
Transparent spore print icon.svg
Spore print is olive-brown
Mycorrhizal fungus.svgEcology is mycorrhizal
Mycomorphbox Edible.pngEdibility is edible

Xerocomellus zelleri, commonly known as Zeller's bolete, is an edible species of mushroom in the family Boletaceae. First described scientifically by American mycologist William Alphonso Murrill in 1912, the species has been juggled by various authors to several genera, including Boletus , Boletellus , and Xerocomus . Found solely in western North America from British Columbia south to Mexico, the fruit bodies are distinguished by their dark reddish brown to nearly black caps with uneven surfaces, the yellow pores on the underside of the caps, and the red-streaked yellow stems. The fungus grows in summer and autumn on the ground, often in Douglas fir forests or on their margins. The development of the fruit bodies is gymnocarpic, meaning that the hymenium appears and develops to maturity in an exposed state, not enclosed by any protective membrane.

Taxonomy

Xerocomellus zelleri was first described by American mycologist William Alphonso Murrill in 1912, based on specimens he found on the campus of the University of Washington. [2] Murrill named it Ceriomyces zelleri [2] before switching the genus later that year to Boletus . [3] In 1944, Walter Henry Snell thought the taxon would be more appropriate in the genus Xerocomus . [4] In 1959, mycologists Rolf Singer, Snell and Esther A. Dick transferred the species to Boletellus , explaining that the microstructure of the trama and the faint ornamentation of the spores were inconsistent with placement in Xerocomus. [5] American mycologist Harry D. Thiers, in his 1976 monograph on North American boletes, claimed that he failed to consistently find ornamentation on the spores of material he collected, and preferred to retain the species in Boletus. [6] In 2011, it was moved to the genus Xerocomellus. [7]

The specific epithet zelleri was chosen by Murrill to honor Professor Sanford Myron Zeller, mycologist at Oregon State University. Zeller accompanied Murrill in his Seattle expedition, and discovered the first specimens of the mushroom. [2] [8]

Description

The cap is typically between 4–12 cm (1+584+34 in) in diameter, [9] initially convex but flattening somewhat in maturity. [10] It is fleshy, with an uneven velvety surface, and dark brown to nearly black; the margin of the cap is a pale cream color. Young specimens are covered by a grayish bloom. [11]

The yellow to dirty yellow flesh inconsistently bruises blue when cut or broken. Boletus zelleri 1621.JPG
The yellow to dirty yellow flesh inconsistently bruises blue when cut or broken.

The tubes that comprise the undersurface of the cap (the hymenium) are up to 1.5 cm (58 in) long and angular, yellow, becoming dirty yellow and finally greenish-yellow; [11] there are 1–2 pores per millimeter on the hymenium surface. [12] They may turn slightly brownish when exposed to the air for a time. The flesh is yellow to dirty yellow, up to 1.5 cm (58 in) thick, [6] and inconsistently bruises blue when cut or broken. [13] The stem is up to 12 cm (4+34 in) tall, 1–3 cm (381+18 in) thick, [9] and swollen toward the base. The stem surface is red or yellowish with red lines, often white or yellow at the base, and solid (that is, not hollow), with fibrous flesh; in maturity the stem ages to yellowish-red to dark red. [10] The spore print is olive-brown; one source notes that creating a spore print may result in "a lot of yellow juice on the paper". [8]

The spores are ellipsoid in shape, smooth, and have dimensions of 12–16 by 4–6  µm, [11] although occasionally there will be some "giant spores" with lengths of up to 24 µm. [6] The basidia, the spore-bearing cells, are 26–35 by 9.5–12 µm, and four-spored. The cystidia are roughly cylindrical and thin-walled, with dimensions of 38–77 by 5.5–14.8 µm. There are no clamp connections present in the hyphae. [5] The fruit body tissue stains a greenish color when a drop of ammonia solution is applied. [14]

Edibility

Xerocomellus zelleri is an edible species, [15] although care should be taken to ensure that specimens collected for consumption are free of fly larvae. [16] In his book 100 Edible Mushrooms, Michael Kuo gave the mushroom an edibility rating of "mediocre". [17] There is no distinguishable odor, and the taste is alternately described as pleasant, [18] mild, [8] or "slightly acidic". [11] The original species description noted that the texture was "slightly mucilaginous". [2] The mushroom is suitable for preserving or drying, [19] or as a "filler" to add bulk to a dish. [17] It is harvested and sold commercially in local markets in British Columbia, Canada. [20]

Similar species

The red-cracked bolete ( Xerocomellus chrysenteron ) has an olive-brown cap that cracks, exposing flesh that ages to pinkish red. Boletellus chrysenteroides , found only in eastern North America, has a velvety to smooth, dark reddish brown, cracked cap with pale exposed flesh. [10] Also similar is Boletus mirabilis . [9]

Fruit body development

A collection from Banner Forest, Kitsap County, Washington, USA Xerocomellus zelleri 60764.jpg
A collection from Banner Forest, Kitsap County, Washington, USA

In 1914, Zeller published a study of the development of the mushroom, made possible by the prolific fruiting of the fungus in Seattle in the fall of 1912. Development was studied by examining thin sections of tissues in different stages of development, and the differentiation of tissues and structures followed by using histological stains. [21] The growth form of Xerocomellus zelleri is called gymnocarpic, meaning that the hymenium appears and develops to maturity in an exposed state, not enclosed by any protective membrane. In this type of development, the cap is formed from hyphae at the top of the stem and subsequently expands by growth along the margins; the hymenium forms later beneath the cap in a direction away from the center. [22]

The mushrooms originate as minute fruit bodies (called "pins" due to their shape) from a yellow mycelium that forms a mat and tends to engulf pine needles. The pins, typically 1–2 mm in diameter, lengthen vertically until they are roughly three or four times longer than they are thick. Until this point, the fruit body is a homogenous mass of tissue. It differentiates simultaneously into cap and stem along a cleavage plane (an axis along which any cell division occurs) from the outside inward, which gives rise to deep furrow encircling the fruit body. The hymenium is formed in the roof of this furrow, growing inward and upward from the outside edge. The cap develops from the upper section of this division, the stem from the lower. [21]

Habitat and distribution

In Lincoln County, Oregon Boletus zelleri.JPG
In Lincoln County, Oregon

This species grows solitarily or in small groups on the ground or in forest duff in mature coniferous forests, occasionally abundant on grassy edges of the forest, rarely on badly decayed conifer logs. It is an ectomycorrhizal mushroom, meaning that the fungal hyphae form sheaths around the rootlets of certain trees, exchanging nutrients with them in a mutualistic relationship. The fungus associates with alder, poplar and other hardwoods, [8] and has been shown in laboratory culture to form ectomycorrhizae with Western Hemlock ( Tsuga heterophylla ). [23] However, the fungus may have saprobic tendencies, as it has been noted to grow under California Redwood (sometimes in the rotted wood of old trunks), a tree not known to form mycorrizhae. [17] [24] It is known to form long rhizomorphs (aggregations of hyphae that resemble roots), and has been noted to be more abundant in sites with buried wood than without. [25] In British Columbia, it occurs from summer to early winter, although it also appears infrequently in early spring. [19] In California, the mushroom often fruits after the rainy period in autumn through to March or April. [6] The dark coloring of the cap make this species difficult to notice, "unless a glimpse of the yellow hymenium is obtained". [2] Fruit bodies are eaten by the American shrew-mole. [26]

Xerocomellus zelleri is distributed in North America in the Pacific Northwest south to California and Mexico. [27] In Mexico, it has been reported in high-altitude cloud forests of Mexican Beech (Fagus mexicana), a rare and endangered habitat. [28] It has also been reported from Tibet, [29] but this may be based on a misidentification.

Chemistry

Xerocomellus zelleri has been shown to contain the phenethylamine alkaloid compounds tyramine, N-methyltyramine, and hordenine, although the chemotaxonomic significance of this is not clear. [30]

See also

Related Research Articles

<i>Xerocomellus chrysenteron</i> Species of fungus

Xerocomellus chrysenteron, formerly known as Boletus chrysenteron or Xerocomus chrysenteron, is a small, edible, wild mushroom in the family Boletaceae. These mushrooms have tubes and pores instead of gills beneath their caps. It is commonly known as the red cracking bolete.

<i>Xerocomus subtomentosus</i> Species of fungus

Xerocomus subtomentosus, commonly known as suede bolete, brown and yellow bolete , boring brown bolete or yellow-cracked bolete, is a species of bolete fungus in the family Boletaceae. The fungus was initially described by Carl Linnaeus in 1753 and known for many years as Boletus subtomentosus. It is edible, though not as highly regarded as other bolete mushrooms.

<i>Boletellus</i> Genus of fungi

Boletellus is a genus of fungi in the family Boletaceae. The genus has a widespread distribution, especially in subtropical regions, and contains about 50 species. The genus was first described by American mycologist William Alphonso Murrill in 1909. The genus name means "small Boletus".

<i>Boletellus obscurecoccineus</i> Species of fungus

Boletellus obscurecoccineus, known as the rhubarb bolete, is a species of fungus in the family Boletaceae, found in Australia, New Guinea, Java, Borneo, Japan, Korea, and Taiwan. It is a distinctive and colourful bolete of the forest floor.

<i>Bothia</i> Genus of fungi

Bothia is a fungal genus in the family Boletaceae. A monotypic genus, it contains the single species Bothia castanella, a bolete mushroom first described scientifically in 1900 from collections made in New Jersey. Found in the eastern United States, Costa Rica, China, and Taiwan, it grows in a mycorrhizal association with oak trees. Its fruit body is chestnut brown, the cap is smooth and dry, and the underside of the cap has radially elongated tubes. The spore deposit is yellow-brown. The edibility of the mushroom is unknown. Historically, its unique combination of morphological features resulted in the transfer of B. castanella to six different Boletaceae genera. Molecular phylogenetic analysis, published in 2007, demonstrated that the species was genetically unique enough to warrant placement in its own genus.

<i>Exsudoporus frostii</i> Species of fungus in the family Boletaceae found in North America

Exsudoporus frostii, commonly known as Frost's bolete or the apple bolete, is a bolete fungus first described scientifically in 1874. A member of the family Boletaceae, the mushrooms produced by the fungus have tubes and pores instead of gills on the underside of their caps. Exsudoporus frostii is distributed in the eastern United States from Maine to Georgia, and in the southwest from Arizona extending south to Mexico and Costa Rica. A mycorrhizal species, its fruit bodies are typically found growing near hardwood trees, especially oak.

<i>Aureoboletus mirabilis</i> Species of fungus

Aureoboletus mirabilis, commonly known as the admirable bolete, the bragger's bolete, and the velvet top, is an edible species of fungus in the Boletaceae mushroom family. The fruit body has several characteristics with which it may be identified: a dark reddish-brown cap; yellow to greenish-yellow pores on the undersurface of the cap; and a reddish-brown stem with long narrow reticulations. Aureoboletus mirabilis is found in coniferous forests along the Pacific Coast of North America, and in Asia. Unusual for boletes, A. mirabilis sometimes appears to fruit on the wood or woody debris of Hemlock, suggesting a saprobic lifestyle. Despite occasional appearances to the contrary, Aureoboletus mirabilis is mycorrhizal, and forms close mutualistic associations with hemlock roots.

<i>Suillus lakei</i> Species of fungus

Suillus lakei, commonly known as the matte Jack, Lake's bolete, or the western painted Suillus, is a species of fungus in the family Suillaceae. It is characterized by the distinctive reddish-brown tufted fibers or small scales on the cap, and the presence of a woolly veil on the stem. The caps can reach diameters of up to 15 cm, while the stems are between 6 and 12 cm long and usually 1–3 cm thick. On the underside of the cap is a layer of spongy yellow to yellow-brown angular pores; these pores are covered with a whitish partial veil when young. A mycorrhizal fungus, S. lakei grows in association with Douglas fir, and is found where this tree occurs. It is native to northwestern North America, but has been introduced to Europe, South America, and New Zealand. The mushroom is edible, but opinions vary considerably as to its quality.

<i>Boletellus ananas</i> Species of fungus

Boletellus ananas, commonly known as the pineapple bolete, is a mushroom in the family Boletaceae, and the type species of the genus Boletellus. It is distributed in southeastern North America, northeastern South America, Asia, and New Zealand, where it grows scattered or in groups on the ground, often at the base of oak and pine trees. The fruit body is characterized by the reddish-pink scales on the cap that are often found hanging from the edge. The pore surface on the underside of the cap is made of irregular or angular pores up to 2 mm wide that bruise a blue color. It is yellow when young but ages to a deep olive-brown color. Microscopically, B. ananas is distinguished by large spores with cross striae on the ridges and spirally encrusted hyphae in the marginal appendiculae and flesh of the stem. Previously known as Boletus ananas and Boletus coccinea, the species was given its current name by William Alphonso Murrill in 1909. Two varieties of Boletellus ananas have been described. Although the mushroom may be considered edible, it is not recommended for consumption.

<i>Tylopilus tabacinus</i> Species of fungus

Tylopilus tabacinus is a species of bolete fungus in the family Boletaceae. It is characterized by a tawny-brown cap measuring up to 17.5 cm (6.9 in) in diameter, and a reticulated stem up to 16.5 cm (6.5 in) long by 6 cm (2.4 in) thick. A characteristic microscopic feature is the distinctive crystalline substance encrusted on the hyphae in the surface of the cap. The species is known from the eastern United States from Florida north to Rhode Island, and west to Mississippi, and from eastern Mexico. It is a mycorrhizal species, and associates with oak and beech trees.

<i>Tylopilus alboater</i> Species of fungus

Tylopilus alboater, called the black velvet bolete, by some, is a bolete fungus in the family Boletaceae. The species is found in North America east of the Rocky Mountains, and in eastern Asia, including China, Japan, Taiwan, and Thailand. A mycorrhizal species, it grows solitarily, scattered, or in groups on the ground usually under deciduous trees, particularly oak, although it has been recorded from deciduous, coniferous, and mixed forests.

<i>Boletus curtisii</i> Species of fungus

Boletus curtisii is a species of fungus in the family Boletaceae. It produces small- to medium-sized fruit bodies (mushrooms) with a convex cap up to 9.5 cm (3.7 in) wide atop a slender stem that can reach a length of 12 cm (4.7 in). In young specimens, the cap and stem are bright golden yellow, although the color dulls to brownish when old. Both the stem and cap are slimy or sticky when young. On the underside of the cap are small circular to angular pores. The mushroom is edible, but not appealing. It is found in eastern and southern North America, where it grows in a mycorrhizal association with hardwood and conifer trees. Once classified as a species of Pulveroboletus, the yellow color of B. curtisii is a result of pigments chemically distinct from those responsible for the yellow coloring of Pulveroboletus.

<i>Boletus auripes</i> Species of fungus

Boletus auripes, commonly known as the butter-foot bolete, is a species of bolete fungus in the family Boletaceae. First described from New York in 1898, the fungus is found in eastern Asia, Central America, and eastern North America from Canada to Florida. It is a mycorrhizal species and typically grows in association with oak and beech trees.

<i>Aureoboletus auriflammeus</i> Species of fungus

Aureoboletus auriflammeus, commonly known as the flaming gold bolete, is a species of bolete fungus in the family Boletaceae. Described as new to science in 1872, it is found in eastern North America, where it grows in a mycorrhizal association with oaks. The caps of the fruit bodies are golden orange, with a yellow pore surface on the underside, and a reticulated (network-like) stem. The edibility of the mushroom is not known.

<i>Xerocomus illudens</i> Species of fungus

Xerocomus illudens is a species of bolete fungus in the family Boletaceae. Described as new to science in 1898, it is found in Asia and North America, where it grows in a mycorrhizal association with oak.

<i>Aureoboletus projectellus</i> Species of fungus

Aureoboletus projectellus is a species of bolete fungus in the family Boletaceae. Found in North America, and recently in Europe, it grows in a mycorrhizal association with pine trees.

<i>Pulveroboletus ravenelii</i> Species of fungus

Pulveroboletus ravenelii, commonly known as Ravenel's bolete or the powdery sulfur bolete, is a species of bolete fungus in the family Boletaceae. Described as new to science in 1853, the widely distributed species is known from Asia, Australia, North America, Central America, and South America. Mycorrhizal with oak, the fungus fruits on the ground singly, scattered, or in groups in woods. Fruit bodies (mushrooms) have convex to flat, yellowish to brownish-red caps up to 10 cm (4 in) in diameter. On the cap underside, the pore surface is bright yellow before turning dingy yellow to grayish brown with age; it stains greenish blue then grayish brown after injury. A cottony and powdery partial veil remains as a ring on the stipe. The mushrooms are edible, and have been used in traditional Chinese medicine and for mushroom dyeing.

<i>Xerocomellus</i> Genus of fungi

Xerocomellus is a genus of fungi in the family Boletaceae. The genus, as it was described in 2008, contained 12 species. However X. rubellus and X. engelii were transferred to the new genus Hortiboletus and X. armeniacus was transferred to the new genus Rheubarbariboletus in 2015. Molecular analysis supports the distinction of Xerocomellus species from Boletus and Xerocomus, within which these species were formerly contained. Xerocomellus in fact is only distantly related to Xerocomus and is most closely related to Tylopilus, Boletus sensu stricto, Porphyrellus, Strobilomyces, and Xanthoconium.

<i>Imleria badia</i> Edible species of fungus in the family Boletaceae found in Europe and North America

Imleria badia, commonly known as the bay bolete, is an edible, pored mushroom found in Eurasia and North America, where it grows in coniferous or mixed woods on the ground or on decaying tree stumps, sometimes in prolific numbers. Both the common and scientific names refer to the bay- or chestnut-coloured cap, which is almost spherical in young specimens before broadening and flattening out to a diameter up to 15 cm (6 in). On the cap underside are small yellowish pores that turn dull blue-grey when bruised. The smooth, cylindrical stipe, measuring 4–9 cm long by 1–2 cm thick, is coloured like the cap, but paler. Some varieties have been described from eastern North America, differing from the main type in both macroscopic and microscopic morphology.

<i>Aureoboletus betula</i> Species of fungus

Aureoboletus betula is a species of mushroom producing fungus in the family Boletaceae. It is commonly known as the Shaggy Stalked Bolete.

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