Agaricus augustus

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Agaricus augustus
Agaricus augustus 2011 G1.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Fungi
Division: Basidiomycota
Class: Agaricomycetes
Order: Agaricales
Family: Agaricaceae
Genus: Agaricus
Species:
A. augustus
Binomial name
Agaricus augustus
Fr.
Synonyms

Psalliota augusta(Fr.) Quél.
Agaricus augustus var. perrarus(Schulzer) Bon & Cappelli [1]

Contents

Agaricus augustus
Information icon.svg
Gills icon.png Gills on hymenium
Convex cap icon.svg Cap is convex
Free gills icon2.svg Hymenium is free
Ring stipe icon.svg Stipe has a ring
Transparent spore print icon.svg
Spore print is brown
Saprotrophic fungus.svgEcology is saprotrophic
Mycomorphbox Choice.pngEdibility is choice

Agaricus augustus, known commonly as the prince, is a basidiomycete fungus of the genus Agaricus .

Taxonomy

According to Heinemann's (1978) popular division of Agaricus, A. augustus belongs to section Arvenses. [2] The system proposed by Wasser (2002) classifies A. augustus within subgenus Flavoagaricus, section Majores, subsection Flavescentes. [3] Moreover, there have been attempts to recognise distinct varieties, namely A. augustus var. augustus Fr., and A. augustus var. perrarus (Schulzer) Bon & Cappelli. The specific epithet augustus is a Latin adjective meaning noble.

Description

The fruiting bodies of Agaricus augustus are large and distinctive agarics. The cap shape is hemispherical during the so-called button stage, and then expands, becoming convex and finally flat, with a diameter from 8–30 cm (3–12 in). [4] The cap cuticle is dry, and densely covered with concentrically arranged, brown-coloured scales on a white to yellow background.

The flesh is thick, firm and white and may discolour yellow when bruised. The gills are crowded and pallid at first, and turn pink then dark brown with maturity. The gills are not attached to the stem—they are free. Immature specimens bear a delicate white partial veil with darker-coloured warts, extending from the stem to the cap periphery.

The stem is clavate and 7–30 cm (3–12 in) tall, and 2–6 cm (342+38 in) thick. [4] In mature specimens, the partial veil is torn and left behind as a pendulous ring adorning the stem. Above the ring, the stem is white to yellow and smooth. Below, it is covered with numerous small scales. [5] Its flesh is thick, white and sometimes has a narrow central hollow. The stem base extends deeply into the substrate. [5]

The mushroom's odour is strong and sweet, similar to almond extract, marzipan or maraschino cherry, due to the presence of benzaldehyde and benzyl alcohol. [6] [7] Its taste has been described as not distinctive.

Under a microscope, the ellipsoid-shaped spores are seen characteristically large at 7–10 by 4.5–6.5 μm. The basidia are 4-spored. The spore mass is coloured chocolate-brown. [2] [8]

A species initially reported from North America, A. subrufescens closely resembles A. augustus in appearance. However, A. subrufescens produces smaller spores, sized 6–7.5 by 4–5 μm.

Agaricus augustus spores 1000x Agaricus.augustus.spores.1000x.jpg
Agaricus augustus spores 1000x

Identification

Agaricus augustus shows a red positive Schaeffer's test reaction. The cap cuticle turns yellow when a 10% potassium hydroxide solution is applied. [2]

Toxic lookalikes include Amanitas which stain yellow when bruised or emit bad odor. [9] Another similar-looking toxic species is Agaricus moelleri . [4]

Habitat

Agaricus augustus has a widespread distribution, occurring throughout Europe, North America, North Africa and Asia. This mushroom is found in deciduous and coniferous woods and in gardens and by roadside verges. The fungus is saprotrophic and terrestrial—it acquires nutrients from decaying dead organic matter and its fruiting bodies occur on humus-rich soil. The species seems adapted to thriving near human activity, for it also emerges from disturbed ground. [10] In Europe, A. augustus fruits in late summer and autumn. [8]

Edibility

The prince under a copper beech at Dumfries House, Ayrshire Agaricus augustus The Prince.JPG
The prince under a copper beech at Dumfries House, Ayrshire

This mushroom is a choice edible, [4] [11] and is collected widely for consumption in Eurasia, the United States, Canada and some parts of Mexico. A. augustus has been implicated in specifically bioaccumulating the metal cadmium, with a quantity of 2.44 mg per kilogram of fresh weight as recorded in one Swiss study. [12] The same phenomenon is true for other edible species of Agaricus, namely A. arvensis , A. macrosporus and A. silvicola , though quantities may vary greatly depending on species, which part of the fruiting body is analysed, and the level of contamination of the substrate. Specimens collected near metal smelters and urban areas have a higher cadmium content. The hymenium contains the highest concentration of metal, followed by the rest of the cap, while the lower part of the stem contains the least. [13]

See also

List of Agaricus species

Related Research Articles

<i>Agaricus subrufescens</i> Species of fungus

Agaricus subrufescens is a species of mushroom, commonly known as almond mushroom, almond agaricus, mushroom of the sun, God's mushroom, mushroom of life, royal sun agaricus, jisongrong, or himematsutake. A. subrufescens is edible, with a somewhat sweet taste and a fragrance of almonds.

<i>Lepista personata</i> Species of fungus

Lepista personata is a species of edible fungus commonly found growing in grassy areas across Europe and is morphologically related to the wood blewit.

<i>Agaricus bernardii</i> Agaric fungus in the family Agaricaceae

Agaricus bernardii, commonly called the salt-loving agaricus, or salty mushroom, is an agaric fungus in the family Agaricaceae. The mushroom's thick stem is usually shorter than the diameter of the cap, which ranges from 5–15 centimetres and is convex to flattened. The cap surface is whitish to buff, and can develop scales or warts in age. The gills are initially pink before turning brown when the spores mature. The flesh turns reddish when it is cut or bruised. It resembles species such as A. bitorquis.

<i>Agaricus abruptibulbus</i> Species of fungus

Agaricus abruptibulbus is a species of mushroom in the genus Agaricus. It is commonly known as the abruptly-bulbous agaricus or the flat-bulb mushroom. First described by the mycologist Charles Horton Peck, this bulbous-stemmed edible species smells slightly of anise or bitter almond, and turns yellow when bruised or cut. The mushroom is medium-sized, with a white, yellow-staining cap on a slender stipe that has a wide, flat bulb on the base.

<i>Agaricus lilaceps</i> Species of fungus

Agaricus lilaceps, also known as the cypress agaricus or the giant cypress agaricus is a species of mushroom. It is among the largest and most choice edible Agaricus species in California. Aside from size, Agaricus lilaceps is characterized by a robust stature, as the stipe often club-shaped.

<i>Agaricus perobscurus</i> Species of fungus

Agaricus perobscurus, commonly known collectively with its close European relative Agaricus lanipes as the princess, is a basidiomycete fungus. A relative of Agaricus augustus, known as the prince, A. perobscurus can be differentiated in several aspects. While the prince is widely distributed in North America, the princess is found only in the San Francisco Bay Area. Besides its smaller size, it is distinguished from Agaricus augustus by a darker-brown cap, a patchy fibrillose stipe surface at youth, lacking densely floccose-scaly, and a different fruiting season. Another commonly closely associated Agaricus species, Agaricus praeclaresquamosus, is toxic. It can be differentiated by its dark-grey cap, a phenolic, rather than an anise odor, and a stipe base which yellows immediately when injured.

<i>Agaricus benesii</i> Species of fungus

Agaricus benesii is an agaric mushroom of the genus Agaricus known in English as the mull mushroom. This mushroom can be distinguished by a white cap that bruises pinkish-red when injured, a scaly lower stipe, and a conifer habitat. Similar to Agaricus californicus and A. xanthodermus, the cap discolors brown in age. A distinguishing feature of A. californicus and A. xanthodermus, however, is a thickened annulus at the margin, a phenolic odor, and a yellowing bruise, instead of red. In the case of Agaricus xanthodermus, it occurs quickly, though faintly to not at all in the case of A. californicus. Another similar species, Agaricus bernardii, also stains red and has white flesh, but differentiates on its larger bulk, a sheathing veil, briny odor, and different habitat, namely grass.

<i>Pholiota flammans</i> Species of fungus

Pholiota flammans, commonly known as the yellow pholiota, the flaming Pholiota, or the flame scalecap, is a basidiomycete agaric mushroom of the genus Pholiota. Its fruit body is golden-yellow in color throughout, while its cap and stem are covered in sharp scales. As it is a saprobic fungus, the fruit bodies typically appear in clusters on the stumps of dead coniferous trees. P. flammans is distributed throughout Europe, North America, and Asia in boreal and temperate regions. Its edibility has not been clarified.

<i>Cystodermella cinnabarina</i> Species of fungus

Cystodermella cinnabarina is a basidiomycete fungus of the genus Cystodermella. Its fruiting body is a small agaric bearing a distinctive reddish-coloured grainy cap. It occurs in coniferous and deciduous forests throughout the world. Prior to 2002, this species belonged to genus Cystoderma, subsection Cinnabarina, under the name Cystoderma cinnabarinum which is still sometimes applied. Another often used synonym is Cystoderma terreyi.

<i>Marasmius rotula</i> Species of fungus

Marasmius rotula is a common species of agaric fungus in the family Marasmiaceae. Widespread in the Northern Hemisphere, it is commonly known variously as the pinwheel mushroom, the pinwheel marasmius, the little wheel, the collared parachute, or the horse hair fungus. The type species of the genus Marasmius, M. rotula was first described scientifically in 1772 by mycologist Giovanni Antonio Scopoli and assigned its current name in 1838 by Elias Fries.

<i>Agaricus deserticola</i> Species of fungus in the family Agaricaceae endemic to southwestern and western North America

Agaricus deserticola, commonly known as the gasteroid agaricus, is a species of fungus in the family Agaricaceae. Found only in southwestern and western North America, A. deserticola is adapted for growth in dry or semi-arid habitats. The fruit bodies are secotioid, meaning the spores are not forcibly discharged, and the cap does not fully expand. Unlike other Agaricus species, A. deserticola does not develop true gills, but rather a convoluted and networked system of spore-producing tissue called a gleba. When the partial veil breaks or pulls away from the stem or the cap splits radially, the blackish-brown gleba is exposed, which allows the spores to be dispersed.

<i>Lactarius rufulus</i> Species of fungus

Lactarius rufulus, commonly known as the rufous candy cap, is a species of fungus in the family Russulaceae. The fruit bodies have fleshy brownish-red caps up to 10 cm (3.9 in) wide, and closely spaced pinkish-yellow gills. The stem is up to 12 cm (4.7 in) long and 3 cm (1.2 in) thick and colored similarly to the cap. The species, known only from California, Arizona, and Mexico, grows on the ground in leaf litter near oak trees. The fruit bodies resembles those of L. rufus, but L. rufulus tends to grow in clusters at a common base, rather than solitarily or in groups. A distinguishing microscopic characteristic is the near absence of large, spherical cells called sphaerocysts that are otherwise common in Lactarius species. Lactarius rufulus mushrooms are edible, and have an odor resembling maple syrup. They have been used to flavor confections and desserts.

<i>Agaricus hondensis</i> Species of fungus in the family Agaricaceae

Agaricus hondensis, commonly known as the felt-ringed agaricus, is a species of fungus in the family Agaricaceae. The species was officially described in 1912 by mycologist William Alphonso Murrill, along with three other Agaricus species that have since been placed in synonymy with A. hondensis. Found in the Pacific Northwest region of North America, A. hondensis fruits in the fall under conifers or in mixed forests.

<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>Protostropharia semiglobata</i> Species of fungus

Protostropharia semiglobata, commonly known as the dung roundhead, the halfglobe mushroom, or the hemispherical stropharia, is an agaric fungus of the family Strophariaceae. A common and widespread species with a cosmopolitan distribution, the fungus produces mushrooms on the dung of various wild and domesticated herbivores. The mushrooms have hemispherical straw yellow to buff-tan caps measuring 1–4 cm (0.4–1.6 in), greyish gills that become dark brown in age, and a slender, smooth stem 3–12 cm (1.2–4.7 in) long with a fragile ring.

<i>Mycena chlorophos</i> Species of agaric fungus in the family Mycenaceae

Mycena chlorophos is a species of agaric fungus in the family Mycenaceae. First described in 1860, the fungus is found in subtropical Asia, including India, Japan, Taiwan, Polynesia, Indonesia, and Sri Lanka, in Australia, and Brazil. Fruit bodies (mushrooms) have pale brownish-grey sticky caps up to 30 mm (1.2 in) in diameter atop stems 6–30 mm (0.2–1.2 in) long and up to a millimeter thick. The mushrooms are bioluminescent and emit a pale green light. Fruiting occurs in forests on fallen woody debris such as dead twigs, branches, and logs. The fungus can be made to grow and fruit in laboratory conditions, and the growth conditions affecting bioluminescence have been investigated.

<i>Lepiota castaneidisca</i> Species of fungus

Lepiota castaneidisca is a species of agaric fungus in the family Agaricaceae. Formally described in 1912, it was for a long time considered the same species as the similar Lepiota cristata until molecular analysis reported in 2001 demonstrated that it was genetically distinct. It is most common in coastal and northern California, and has also been recorded in Mexico. A saprobic species, it is usually found under redwood and Monterey cypress. Its fruit bodies (mushrooms) have white caps with an orange-red to orange-brown center that measure up to 3.2 cm (1.3 in) wide. The cream-colored to light pink stems are up to 6.5 cm (2.6 in) long by 0.2–0.6 cm (0.1–0.2 in) thick, and have a ring. L. castaneidisca can be distinguished from other similar Lepiota species by differences in habitat, macroscopic, or microscopic characteristics.

<i>Tricholoma vernaticum</i> Species of fungus

Tricholoma vernaticum is an agaric fungus of the genus Tricholoma native to the Pacific Northwest region of the United States. The fungus was originally described in 1976 as a species of Armillaria when that genus was more inclusive; it received its current name twenty years later. The stout fruit bodies (mushrooms) have moist white to grayish caps, a membranous ring on the stipe, and an odor resembling cucumbers. Mycorrhizal with conifers, the fungus fruits in the spring or early summer, with its mushrooms appearing on the ground singly or in groups at high elevations, often at the edge of melting snowbanks. The edibility of the mushroom is unknown, but it has a strong unpleasant odor and a mealy taste.

<i>Russula densifolia</i> Species of agaric fungus

Russula densifolia, commonly known as the crowded russula or the reddening russula, is a species of agaric fungus in the family Russulaceae. It was first described in 1833 and given its current name in 1876. A widespread species, it is found in Asia, Europe, and North America, where it fruits on the ground in mixed and deciduous forests. Fruit bodies (mushrooms) are robust and squat, with caps up to 14.5 cm (5.7 in) in diameter, and stems that are 2–7.5 cm (0.8–3.0 in) long by 1.2–2.5 cm (0.5–1.0 in) thick. The mushrooms are characterized by the red and then black color changes that occur in the flesh when it is bruised, and a relatively thick cap cuticle. Although the mushroom is sold as an edible species in some areas of Asia, it is mild to moderately toxic, and may cause gastrointestinal upset if consumed. Several bioactive compounds have been isolated and identified from the mushroom.

<i>Paralepista flaccida</i> Species of fungus

Paralepista flaccida is a species of mushroom found across the Northern Hemisphere. It is known to form fairy rings.

References

  1. "Agaricus augustus taxon record details at Index Fungorum". Index Fungorum. Archived from the original on 2011-06-10. Retrieved 2010-01-14.
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  3. Lacheva, Maria (January 2006). "Genus Agaricus L. in Bulgaria–Taxonomy, Ecology, Chorology and Economic Importance (in Bulgarian)" (PDF). Agrarian University - Plovdiv: 18–19.[ permanent dead link ]
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  7. The Mycological Society of America (2002). "The anise-like odor of Clitocybe odora, Lentinellus cochleatus and Agaricus essettei". Mycologia. 94 (3): 373–376. doi:10.2307/3761770. JSTOR   3761770. PMID   21156507.
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  9. Meuninck, Jim (2017). Foraging Mushrooms Oregon: Finding, Identifying, and Preparing Edible Wild Mushrooms. Falcon Guides. p. 109. ISBN   978-1-4930-2669-2.
  10. Arora D. (1986). Mushrooms Demystified: a Comprehensive Guide to the Fleshy Fungi . Berkeley, Calif: Ten Speed Press. p.  45. ISBN   0-89815-169-4. Google Books
  11. Boa ER. (2006). "Champignons Comestibles Sauvages" [Edible Wild Mushrooms] (in French). Food and Agriculture Organization of the United Nations. p. 141. ISBN   92-5-205157-0.
  12. Neukom P. (2005). "Métaux toxiques dans les champignons comestibles. Danger pour la santé des consommateurs?". Bulletin Suisse de Mycologie (in French). 15 (4): 170–171. ISSN   0373-2959.
  13. Kalač P.; Svoboda L.; Havlíčková B. (2004). "Contents of cadmium and mercury in edible mushrooms". Journal of Applied Biomedicine. 2: 15–20. doi: 10.32725/jab.2004.002 . ISSN   1214-0287.