''Agaricus pocillator'', a woodland mushroom, is distributed through southeastern North America in ranges at least as far north as

Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolita ...

. It can be distinguished in the field by its dark center, its small,

bulb In botany, a bulb is structurally a short stem with fleshy leaves or leaf basesBell, A.D. 1997. ''Plant form: an illustrated guide to flowering plant morphology''. Oxford University Press, Oxford, U.K. that function as food storage organs duri ...

ous base, which stains

yellow Yellow is the color between green and orange on the spectrum of light. It is evoked by light with a dominant wavelength of roughly 575585 nm. It is a primary color in subtractive color systems, used in painting or color printing. In the R ...

, and its relatively slight stature. It is very similar to ''

Agaricus placomyces ''Agaricus placomyces'' is a toxic basidiomycete fungus of the genus Agaricus. It is found in North America; the Eurasian populations formerly known by the same scientific name are nowadays known as '' A. moelleri'', while the present species m ...

'', but is a slightly smaller

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 ...

with a scalier

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 ...

and a more northern range within the United States. ''A. pocillator'' is inedible, and several other yellow-staining ''

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 ...

'' species are poisonous. Hikers are often warned to avoid eating it when spotted.

Ecology

They are

saprobic Saprotrophic nutrition or lysotrophic nutrition is a process of chemoheterotrophic extracellular digestion involved in the processing of decayed (dead or waste) organic matter. It occurs in saprotrophs, and is most often associated with fungi ( ...

, meaning that they survive by decomposing

dead Death is the irreversible cessation of all biological functions that sustain an organism. For organisms with a brain, death can also be defined as the irreversible cessation of functioning of the whole brain, including brainstem, and brain ...

or decaying

organic material Organic matter, organic material, or natural organic matter refers to the large source of carbon-based compounds found within natural and engineered, terrestrial, and aquatic environments. It is matter composed of organic compounds that have c ...

. They often grow alone or gregariously under

hardwood Hardwood is wood from dicot trees. These are usually found in broad-leaved temperate and tropical forests. In temperate and boreal latitudes they are mostly deciduous, but in tropics and subtropics mostly evergreen. Hardwood (which comes from ...

s and in mixed woods throughout the southeast of

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

Description

Their

is 3–10 cm, convex to broadly convex or nearly flat in age, sometimes with an obscure, darker bump, and dry. The top is mainly whitish to dingy, developing vaguely concentric brownish to grayish scales towards the center. Their

gill 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 ...

s are free from 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 ...

, close, and white, becoming pinkish, then brown. The

is 4–8 cm long, 0.5–1 cm thick, more or less equal, and contains a small

ous base that bruises yellow. In addition, it has a ring that typically persists into maturity, and a partial veil when covering the gills not developing dark droplets. 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 muscle Skeletal muscles (commonly referred to as mu ...

is white throughout and staining bright yellow in the base. The

taste The gustatory system or sense of taste is the sensory system that is partially responsible for the perception of taste (flavor). Taste is the perception produced or stimulated when a substance in the mouth reacts chemically with taste receptor ...

is not distinctive or somewhat unpleasant. In contrast, the

odor An odor (American English) or odour (English in the Commonwealth of Nations, Commonwealth English; American and British English spelling differences#-our, -or, see spelling differences) is caused by one or more volatilized chemical compounds ...

is often unpleasant (phenolic), but sometimes not distinctive. 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 brown. Chemical reactions involve combining the

and

yellow with

potassium hydroxide Potassium hydroxide is an inorganic compound with the formula K OH, and is commonly called caustic potash. Along with sodium hydroxide (NaOH), KOH is a prototypical strong base. It has many industrial and niche applications, most of which exp ...

(KOH). The

spore 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 ...

s are 4.5-6 x 3-3.8 µm and elliptical.

References

External links

Index Fungorum
{{Taxonbar, from=Q4691344 pocillator Inedible fungi Fungi of North America Fungi described in 1941 Taxa named by William Alphonso Murrill

Ecology

Description

See also

References

External links