''Agaricus semotus'' is a woodland mushroom of the fungus

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

Agaricales The Agaricales are an order (biology), order of fungi in the division (mycology), division Basidiomycota. As originally conceived, the order contained all the agarics (gilled mushrooms), but subsequent research has shown that not all agarics are ...

''. Like many of its relatives, it can be found spread throughout wooded, moist areas in the southern United States, and has been found in areas ranging from

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

. It is also indigenous to

Great Britain Great Britain is an island in the North Atlantic Ocean off the north-west coast of continental Europe, consisting of the countries England, Scotland, and Wales. With an area of , it is the largest of the British Isles, the List of European ...

and

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

. ''A. semotus'' has also been collected in

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

. Although various authors disagree about its edibility, its modest size prevents it from being a significant source of nutrition.

Description

The

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. The origin of the word "cap" comes from the Old French word "chapeau" which means "head co ...

is 2–7 cm in diameter, initially convex while flattening with age; it typically has a low umbo–a raised, conical mound in the center of the cap.Google Books
/ref> The surface color can range from a lighter cream to a darker tan, with brownish scales thinning out towards the margin of the cap. The

gill A gill () is a respiration organ, respiratory organ that many aquatic ecosystem, aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow r ...

s are free from the stalk and packed closely together, showing a pink to salmon color in youth and aging to a darker brown. The stalk is 3–7 cm tall and 0.4–0.8 cm broad, and bruises yellow when handled. A

ring (The) Ring(s) may refer to: * Ring (jewellery), a round band, usually made of metal, worn as ornamental jewelry * To make a sound with a bell, and the sound made by a bell Arts, entertainment, and media Film and TV * ''The Ring'' (franchise), a ...

or remnants thereof are often evident, while the

partial veil In mycology, a partial veil (also called an inner veil, to differentiate it from the "outer", or universal veil) is a temporary structure of tissue found on the fruiting bodies of some Basidiomycota, basidiomycete fungus, fungi, typically agarics. ...

is often absent or minutely visible along the margin of the cap. 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 throughout and stains yellow when bruised. 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 warm orange ("tussock") color spore print. ...

dark brown Dark Brown may refer to: * Dark brown * Dark Brown (1957 film), an Australian television film * Dark Brown (1963 film), another version of the above {{dab ...

. The taste is said to be slightly reminiscent of anise or almond while the odor is often more distinctive. The

spore In biology, a spore is a unit of sexual reproduction, sexual (in fungi) or asexual reproduction that may be adapted for biological dispersal, dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores fo ...

s are 4.5–5.5 x 3–3.5

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 ...

, smooth,

nonamyloid In mycology a tissue or feature is said to be amyloid if it has a positive amyloid reaction when subjected to a crude chemical test using iodine as an ingredient of either Melzer's reagent or Lugol's solution, producing a blue to blue-black staini ...

, and elliptical. 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 ...

, the spore-bearing cells, are 4-spored, while the

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 ...

(relatively large non-spore producing cells typically found on the

hymenium The hymenium is the tissue layer on the hymenophore of a fungal fruiting body where the cells develop into basidia or asci, which produce spores. In some species all of the cells of the hymenium develop into basidia or asci, while in oth ...

) are roughly club-shaped with thin walls.

Edibility

It has been reported as edible, Internet Archive"> Internet Archive
/ref> but others claim that it may cause gastrointestinal discomfort.Google Books
/ref> Arora notes that these mushrooms are "rarely collected because of their small size".

Phylogenetics

Phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

analysis shows ''A. semotus'' to be closely related to a

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

known as subgenus ''Flavoagaricus'' or section ''Arvense''. This clade also includes the species '' A. silvicola'', '' A. arvensis'' and '' A. abruptibulbus''; these species also bruise yellow, and smell of almonds.Mitchell AD, Bresinsky A. (1999). "Phylogenetic relationships of ''Agaricus'' species based on ITS-2 and 28S ribosomal DNA sequences". ''

Mycologia ''Mycologia'' is a peer-reviewed scientific journal that publishes papers on all aspects of the fungi, including lichens. It first appeared as a bimonthly journal in January 1909, published by the New York Botanical Garden under the editorship of W ...

'', 91(5): 811–19. However, analysis of additional species suggests ''A. semotus'' properly belongs to the distinct subgenus ''Minores'', which includes the smaller relatives of the ''Arvense'' clade (and was formerly included there).

References

{{DEFAULTSORT:Agaricus Semotus semotus Fungi of North America Fungi of Europe Fungi of New Zealand Fungus species

Description

Edibility

Phylogenetics

See also

References