''Protostropharia semiglobata'', commonly known as the dung roundhead, the halfglobe mushroom, or the hemispheric stropharia, is an

agaric An agaric () is a type of fungus fruiting body characterized by the presence of a pileus (cap) that is clearly differentiated from the stipe (stalk), with lamellae (gills) on the underside of the pileus. In the UK, agarics are called "mushroom ...

fungus of the family

Strophariaceae The Strophariaceae are a family of fungi in the order Agaricales. Under an older classification, the family covered 18 genera and 1316 species. The species of Strophariaceae have red-brown to dark brown spore prints, while the spores themselves a ...

. A common and widespread species with a cosmopolitan distribution, the fungus produces

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 ...

s on the dung of various wild and domesticated herbivores. The mushrooms have hemispherical straw yellow to

buff Buff or BUFF may refer to: People * Buff (surname), a list of people * Buff (nickname), a list of people * Johnny Buff, ring name of American world champion boxer John Lisky (1888–1955) * Buff Bagwell, a ring name of American professional ...

tan Tan or TAN may refer to: Businesses and organisations * Black and Tans, a nickname for British special constables during the Irish War of Independence. By extension "Tans" can now also colloquially refer to English or British people in general, es ...

caps Caps are flat headgear. Caps or CAPS may also refer to: Science and technology Computing * CESG Assisted Products Service, provided by the U.K. Government Communications Headquarters * Composite Application Platform Suite, by Java Caps, a Ja ...

measuring , greyish

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 ...

that become dark brown in age, and a slender, smooth stem long with a fragile

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 ...

Taxonomy

The species was first described as ''Agaricus semiglobatus'' by

August Batsch August Johann Georg Karl Batsch (28 October 1761 – 29 September 1802) was a German naturalist. He was a recognised authority on mushrooms, and also described new species of ferns, bryophytes, and seed plants. Life and career Batsch was born ...

in 1786. It has had a complicated taxonomic history, having been shuffled to many different genera. In addition to ''Agaricus'' the species has been placed in ''

Coprinus ''Coprinus'' is a small genus of mushroom-forming fungi consisting of ''Coprinus comatus''the shaggy ink cap (British) or shaggy mane (American)and several of its close relatives. Until 2001, ''Coprinus'' was a large genus consisting of all ag ...

'', '' Geophila'', ''

Psalliota ''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 ...

'', and ''

Psilocybe ''Psilocybe'' ( ) is a genus of gilled mushrooms, growing worldwide, in the family Hymenogastraceae. Most or nearly all species contain the psychedelic compounds psilocybin and psilocin. Taxonomy Taxonomic history A 2002 study of the mol ...

''. French mycologist

Lucien Quélet Lucien Quélet in 1869 Lucien Quélet (14 July 1832 – 25 August 1899) was a French naturalist and mycologist. Quélet discovered several species of fungi and was the founder of the Société mycologique de France, a society devoted to mycolo ...

gave it its most commonly used name in 1872 when he transferred it to '' Stropharia''. In 2013, Scott Redhead made it the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specime ...

of ''

Protostropharia ''Protostropharia'', is a coprophilous fungi, coprophilous agaric fungal genus that produces glutinous, mostly yellowish to yellow brown basidiocarp, fruit bodies. Characteristically most form chrysocystidia and rather large, smooth, violaceous b ...

'', a new genus circumscribed to contain ''Stropharia'' species characterized by the formation of astrocystidia rather than

acanthocytes Acanthocyte (from the Greek word ἄκανθα ''acantha'', meaning 'thorn'), in biology and medicine, refers to an abnormal form of red blood cell that has a spiked cell membrane, due to thorny projections. A similar term is spur cells. Often ...

on their

mycelium Mycelium (plural mycelia) is a root-like structure of a fungus consisting of a mass of branching, thread-like hyphae. Fungal colonies composed of mycelium are found in and on soil and many other substrates. A typical single spore germinates ...

. A

form Form is the shape, visual appearance, or configuration of an object. In a wider sense, the form is the way something happens. Form also refers to: *Form (document), a document (printed or electronic) with spaces in which to write or enter data ...

''sterilis'' and two

varieties Variety may refer to: Arts and entertainment Entertainment formats * Variety (radio) * Variety show, in theater and television Films * ''Variety'' (1925 film), a German silent film directed by Ewald Andre Dupont * ''Variety'' (1935 film), ...

, ''minor'' and ''radicata'', described by F.H. Møller in 1945, are no longer considered to have independent taxonomic significance. The specific epithet ''semiglobata'' is

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

for "half-spherical", and refers to the shape of the cap. It is commonly known as the halfglobe mushroom, the hemispheric stropharia, the round stropharia, or the dung roundhead.

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 ...

is obtuse to hemispherical in shape, reaching a diameter of . The cap surface is smooth and sticky, and initially has a light yellow color that fades in maturity to dull yellow or whitish. The

have an adnate attachment to the stem with a slight decurrent tooth. They are distantly spaced and broad–about 6–8 mm; mature gills become ventricose (swollen). The gills are initially grayish, but become purplish brown to dark purple as the spores mature. The edges of the gills are white and fringed. The stem is long by thick, with a bulbous base. Initially filled with a cottony pith, the stem becomes hollow in maturity. A delicate

forms an annular zone on the mid to upper portion of the stem that may be darkened from spore deposits. Above the annular zone, the stem is covered with fine silk-like hairs; below, it is sticky. The stem tissue is white with a yellowish pith. The flesh has no distinctive odor, and a taste that is mild to slightly bitter. The fruit bodies have been listed as

edible An edible item is any item that is safe for humans to eat. "Edible" is differentiated from "eatable" because it does not indicate how an item tastes, only whether it is fit to be eaten. Nonpoisonous items found in nature – such as some mushroo ...

by some authors, but

poisonous Poison is a chemical substance that has a detrimental effect to life. The term is used in a wide range of scientific fields and industries, where it is often specifically defined. It may also be applied colloquially or figuratively, with a broa ...

by others; even when not toxic, mushrooms that grow on dung are usually considered unpalatable, though the common mushroom is an obvious counter-example. The mushroom produce a dark purple

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 ...

. The thick-walled spores are ellipsoidal, smooth, and have a small apical

germ pore A germ pore is a small pore in the outer wall of a fungal spore through which the germ tube exits upon germination. It can be apical or eccentric in its location, and, on light microscopy, may be visualized as a lighter coloured area on the cell ...

; they measure 16.1–19.0 by 8.8–11.0 μm. The

basidia A basidium () is a microscopic sporangium (a spore-producing structure) found on the hymenophore of fruiting bodies of basidiomycete fungi which are also called tertiary mycelium, developed from secondary mycelium. Tertiary mycelium is highly- ...

(spore-bearing cells) are four-spored, club-shaped, hyaline (translucent), and measure 33–40 by 13–14.6 μm.

Similar species

Other mushrooms that resemble ''Protostropharia semiglobosa'' include '' Stropharia dorsispora'', '' S. luteonitens'', and '' Panaeolus semiovatus''.

Habitat and distribution

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 ( ...

species, the fungus fruits in small groups on dung, in soil containing manure, on lawns, grasslands, or in livestock corrals. It has been recorded on the dung of a variety of wild and domesticated herbivores and

ungulate Ungulates ( ) are members of the diverse clade Ungulata which primarily consists of large mammals with hooves. These include odd-toed ungulates such as horses, rhinoceroses, and tapirs; and even-toed ungulates such as cattle, pigs, giraffes, ...

s, including rabbit, sheep, cow, buffalo, moose, bear, and wallaby. In some instances, the dung substrate is under moss so that it appears as if the mushroom is growing from the moss. Fruits bodies sometimes occur with another dung-loving fungus, '' Deconica coprophila''. A widespread and common species, ''P. semiglobosa'' has a cosmopolitan distribution, having been recorded from northern Asia, Australia, Europe, Central and South America, North America, North Africa, and New Zealand. It is thought to have been introduced to Australia with imported domestic stock.

References

External links

* {{Taxonbar, from=Q46810615 Strophariaceae Fungi of Africa Fungi of Asia Fungi of Australia Fungi of Central America Fungi of Europe Fungi of New Zealand Fungi of North America Fungi of South America Fungi described in 1786 Taxa named by August Batsch