''Agaricus moelleri'', also known as the inky mushroom, or dark scaled mushroom, is a large

mushroom A mushroom or toadstool is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground, on soil, or on its food source. ''Toadstool'' generally denotes one poisonous to humans. The standard for the name "mushroom" is t ...

of the genus ''

Agaricus ''Agaricus'' is a genus of mushrooms containing both edible and poisonous species, with over 400 members worldwide and possibly again as many disputed or newly-discovered species. The genus includes the common ("button") mushroom (''Agaricus bisp ...

''. It appears occasionally in most kinds of woodland, during late summer, in northern

temperate zones In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout t ...

Taxonomy

For many years ''Agaricus moelleri'' was erroneously accredited with the binomial ''Agaricus placomyces'' by some British authors. The

epithet An epithet (, ), also byname, is a descriptive term (word or phrase) known for accompanying or occurring in place of a name and having entered common usage. It has various shades of meaning when applied to seemingly real or fictitious people, di ...

''placomyces'' was in fact given to a North American species of ''Agaricus'' by

Charles Horton Peck Charles Horton Peck (March 30, 1833 – July 11, 1917) was an American mycologist of the 19th and early 20th centuries. He was the New York State Botanist from 1867 to 1915, a period in which he described over 2,700 species of North American fun ...

in 1878 (now known as ''Agaricus praeclaresquamosus'' A.E.Freeman 1979). The current binomial ''Agaricus moelleri'' was published in 1976 by the Ukrainian mycologist Solomon P. Wasser.

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. Caps typically have a visor, or no brim at all. They are popular in casual and informal se ...

has a greyish-brown patch in the centre and cold grey-brown scaling on the surrounding off-white background. It is in diameter, and yellows when bruised. It is ovate when young, flattening later. The

stem Stem or STEM may refer to: Plant structures * Plant stem, a plant's aboveground axis, made of vascular tissue, off which leaves and flowers hang * Stipe (botany), a stalk to support some other structure * Stipe (mycology), the stem of a mushro ...

has a drooping

ring Ring 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 :(hence) to initiate a telephone connection Arts, entertainment and media Film and ...

, and stains yellow very easily when bruised, this colour then changes to brown over time. The stem

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 muscle Skeletal muscles (commonly referred to as mu ...

bruises yellow only faintly, and is more noticeable in the base. The

gills A gill () is a respiratory organ that many 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 respiration on land provided they are ...

are crowded, and free, as is typical for an ''Agaricus''. They are pink on young specimens, but brown to black on older fruit bodies. The flesh is white and does not change colour on cutting. It is noted by some authors as smelling like ink, iodoform, sweat, or mouldy straw. 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, f ...

are 4–6 x 3–4

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 Unit ...

, and are elliptical. The odour resembles phenol. A similar species occurring in North America, ''Agaricus praeclaresquamosus'' A.E. Freeman 1979, has several variants, some of which are larger. The rare '' Agaricus phaeolepidotus'' also has the iodoform, or ink smell, but has browner cap scales, and stains yellow less readily.

Distribution and habitat

''Agaricus moelleri'' is found in the

of the

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 as being in the same celestial hemisphere relative to the invariable plane of the solar system as Earth's Nort ...

. North America, Asia Britain, and Europe, growing in mixed forests and woods. It is widespread, but can be locally rare, and favors rich alkaline woodland, or parkland.

Toxicity

In the same fashion as the yellow stainer (''

Agaricus xanthodermus ''Agaricus xanthodermus'', commonly known as the yellow-staining mushroom or simply the yellow-stainer, is a mushroom of the genus ''Agaricus'', which displays a strong yellow colouration at the base of the stem when cut. It is poisonous for mos ...

''), ''Agaricus moelleri'' can produce gastrointestinal symptoms for some people but not others, when ingested. It is considered toxic.

Similar species

Agaricus hondensis ''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'' specie ...

'' is similar, with a pinkish tint and firmer flesh.

References

External links

English Country Garden
{{Taxonbar, from=Q1614842 moelleri Fungi of Europe Fungi of North America Fungi described in 1976