''Psathyrella ammophila'' is a species of

fungus A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from t ...

in the family

Psathyrellaceae The Psathyrellaceae are a family of dark-spored agarics that generally have rather soft, fragile fruiting bodies, and are characterized by black, dark brown, rarely reddish, or even pastel-colored spore prints. About 50% of species produce fruit ...

and is found throughout Europe. Commonly known as the dune brittlestem, this

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 ...

primarily grows on sand dunes near

marram grass ''Ammophila'' (synonymous with ''Psamma'' P. Beauv.) is a genus of flowering plants consisting of two or three very similar species of grasses. The common names for these grasses include marram grass, bent grass, and beachgrass. These grasses ar ...

, feeding saprotrophically on the decaying roots. The season of growth is generally May to November. ''P. ammophila'' is variable in appearance, changing colour and shape during its lifespan. Initially bell-shaped and tan or pale brown, the cap gradually flattens and darkens, becoming dark brown with a depressed shape as it ages.

Taxonomy

''Psathyrella ammophila'' was first described in 1868 by

Michel Charles Durieu de Maisonneuve Michel Charles Durieu de Maisonneuve (7 December 1796 – 20 February 1878) was a French soldier and botanist who was a native of Saint-Eutrope-de-Born in the department of Lot-et-Garonne. He studied at École Militaire de Brienne, and later at t ...

and Joseph-Henri Léveillé in one of Durieu de Maisonneuve's publications on the flora and fauna of Algeria, ''Exploration scientifique de l'Algérie: Sciences naturelles, botanique''. They gave it the scientific name ''Agaricus ammophilus''. The species was identified and described a further five times under different names, until 1960, when the botanist P.D. Orton gave the definitive classification in the journal ''Transactions of the British Mycological Society'' (now ''

Fungal Biology ''Fungal Biology'' is a scientific journal that publishes peer-reviewed papers on all aspects of basic and applied research of the fungi, including lichens, yeasts, oomycetes, and slime moulds. A publication of the British Mycological Society, it ...

''). The genus name ''Psathyrella'' is a diminutive form of ''Psathyra'', derived from the Greek word meaning "friable", ''psathuros'' (ψαθυρος). This name, like the common name brittlestem for many of the ''Psathyrella'' species, is related to the fragile nature of the cap and stem. The specific epithet ''ammophila'' originates from the Greek words ''ammos'' (ἄμμος), meaning sand, and ''phillia'' (ϕιλος), meaning lover, a reference to the mushroom's sand dune habitat.

Description

Typically small- to medium-sized, ''P. ammophila'' is found growing terrestrial or in small clumps near

. The cap is a light clay-brown or tan when younger and about in diameter. Although the cap is generally smooth, it possesses microscopically tiny hairs and is often coated with sand particles. The tissue is not

hygrophanous The adjective hygrophanous refers to the color change of mushroom tissue (especially the pileus surface) as it loses or absorbs water, which causes the pileipellis to become more transparent when wet and opaque when dry. When identifying hygrop ...

and therefore does not change colour with moisture loss and absorption, but the mushrooms do darken to a dark brown as they age. Cap shape begins as campanulate or convex, gradually flattening and possibly becoming depressed in shape. The gills of ''P. ammophila'' are crowded and attached to the stem usually broadly (adnate) but occasionally narrowly (adnexed). At a very young age they may be a pallid brown, but for most of the lifespan are dark brown, sometimes turning black. The stipe/stem is light grey to pale brown and centrally attached to the cap. The surface is smooth, sometimes with small vertical ridges. It is deeply rooted in the substrate for feeding on the roots of marram grass and for stability in its sand dune habitat. Above ground, its height is typically tall and its diameter is slender, about . There is no ring. 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- ...

bear four spores. The spores are dark brown and smooth, ellipsoid in shape, and 10 to 11 µm × 6 to 7 µm. There is a large

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 ...

on each spore. Flesh of the cap and stem is pale, thin, and brittle. Neither the taste nor the odour of the mushroom is distinctive, and it is considered inedible, though not particularly noted as being toxic. ''

Conocybe dunensis ''Conocybe'' is a genus of mushrooms with ''Conocybe tenera'' as the type species and at least 243 other species. There are at least 50 different species in North America. Most have a long, thin fragile stipe and are delicate, growing in grassl ...

'' is a similar species that is mainly differentiated from ''P. ammophila'' by the rust colour of its gills.

Distribution and habitat

''Psathyrella ammophila'' has a wide but sparse distribution throughout the European continent and in limited coastal locations outside Europe, with records of collection in Algeria, New Zealand, and Canada. It can sometimes be found near the shoreline, inside the

littoral zone The littoral zone or nearshore is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely inundated), to coastal a ...

, but is most often encountered in more stable and established sand dunes and

dune slack An interdunal wetland, interdunal pond or dune slack is a water-filled depression between coastal sand dunes. It may be formed either by wind erosion or by dunal encroachment on an existing wetland. The wind erosion process involves wind scooping ...

s inland. The presence of

nearby is a key aspect of its habitat, as it has a symbiotic (specifically,

commensal Commensalism is a long-term biological interaction (symbiosis) in which members of one species gain benefits while those of the other species neither benefit nor are harmed. This is in contrast with mutualism, in which both organisms benefit fro ...

) relationship with the plants, using their decaying roots as food. The mushrooms grow singly or in clumps and are, to some degree, sympatric with the fly ''

Delia albula ''Delia albula'' is a species of fly in the family Anthomyiidae The Anthomyiidae are a large and diverse family of Muscoidea flies. Most look rather like small houseflies, but are commonly drab grey. The genus ''Anthomyia'', in contrast, is ...

''. The

fungivorous Fungivory or mycophagy is the process of organisms consuming fungi. Many different organisms have been recorded to gain their energy from consuming fungi, including birds, mammals, insects, plants, amoebas, gastropods, nematodes, bacteria and othe ...

larvae of the fly develops in ''P. ammophila'' parasitically, though will also attack other fungi.

References

External link

{{Taxonbar, from=Q7254038 Psathyrellaceae Taxa named by Joseph-Henri Léveillé Fungi described in 1868