''Clitocybe agrestis'' is a species of

agaric An agaric () is a type of fungal 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. It is a type of mushroom (or toadstool) ...

fungus. Widely distributed in Europe, it was described as new to science in 1969 by the Finnish mycologist Harri Harmaja. Fruitbodies are

poisonous A poison is any chemical substance that is harmful or lethal to living organisms. 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 figurati ...

as they contain the toxin

muscarine Muscarine, L-(+)-muscarine, or muscarin is a Secondary metabolite, natural product found in certain mushrooms, particularly in ''Inocybe'' and ''Clitocybe'' species, such as the deadly ''Clitocybe dealbata, C. dealbata''. Mushrooms in the g ...

Taxonomy

''Clitocybe agrestis'' was formally described by the Finnish mycologist Harri Harmaja in 1969. The

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

was collected on 11 October 1968 along a roadside near Läby in

Uppland Uppland is a historical province or ' on the eastern coast of Sweden, just north of Stockholm, the capital. It borders Södermanland, Västmanland and Gästrikland. It is also bounded by lake Mälaren and the Baltic Sea. The name literally ...

, Sweden; an isotype (duplicate) is preserved at the

herbarium A herbarium (plural: herbaria) is a collection of preserved plant biological specimen, specimens and associated data used for scientific study. The specimens may be whole plants or plant parts; these will usually be in dried form mounted on a sh ...

of the

University of Michigan The University of Michigan (U-M, U of M, or Michigan) is a public university, public research university in Ann Arbor, Michigan, United States. Founded in 1817, it is the oldest institution of higher education in the state. The University of Mi ...

. The

species epithet Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In Taxonomy (biology), taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany) ...

''agrestis'' means "of fields".

Description

The cap ( pileus measures 2–5 cm across and is

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 The pileipellis is the uppermost layer of hyphae in the pileus of a fungal fr ...

—that is, it changes shade as it dries—and translucent‑striate up to halfway from the margin to the disc. When moist the cap is various shades of beige, with a slightly paler, bent‑down margin; in dried specimens it becomes a dull, dirty brown. Young caps are slightly convex, flattening to plane and eventually developing a shallow central depression. The stipe is 2–4 cm long and 2–5 mm thick, typically matching the cap in colour or a touch paler. It tapers little or not at all, remains solid for some time before hollowing out, and bears a sparse whitish tomentum and occasional

rhizoid Rhizoids are protuberances that extend from the lower epidermal cells of bryophytes and algae. They are similar in structure and function to the root hairs of vascular land plants. Similar structures are formed by some fungi. Rhizoids may be un ...

s at the base. The surface is dry, matt and smooth. The

lamellae Lamella (: lamellae) means a small plate or flake in Latin, and in English may refer to: Biology * Lamella (mycology), a papery rib beneath a mushroom cap * Lamella (botany) * Lamella (surface anatomy), a plate-like structure in an animal * Lame ...

are obliquely adnate to faintly decurrent, forming an angle of 35–60°. They occur in three tiers, about 30 reach the stipe, and are often triangular, broadest (4–5 mm) near the stipe and narrowing towards the edge. When fresh they are whitish to faintly brownish; in dried specimens they acquire dirty brown tones similar to the cap and stipe. The smell is faintly fruity—often likened to strawberries—and becomes more pronounced as the fruit bodies dry. The taste is mild and fungoid. Microscopically, the spores measure 4.5–5.8 by 2.9–3.3

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 ...

, are broadly

ellipsoid An ellipsoid is a surface that can be obtained from a sphere by deforming it by means of directional Scaling (geometry), scalings, or more generally, of an affine transformation. An ellipsoid is a quadric surface; that is, a Surface (mathemat ...

to oblong with an obtuse base, and often occur in tetrads; the apiculus is about 0.6–0.7 by 0.3–0.4 μm. 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. ...

is pinkish‑buff. The cap cuticle (epicutis) is 60–100 μm thick, comprising subparallel to interwoven

hypha A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one o ...

e 1.5–4.5 μm wide with faint intracellular pigment; the underlying subcutis is not clearly differentiated.

Habitat and distribution

''C. agrestis'' is

saprotrophic 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 ...

fruiting gregariously to in small tufts in man‑made open habitats such as stubble fields (

oat The oat (''Avena sativa''), sometimes called the common oat, is a species of cereal grain grown for its seed, which is known by the same name (usually in the plural). Oats appear to have been domesticated as a secondary crop, as their seeds ...

rye Rye (''Secale cereale'') is a grass grown extensively as a grain, a cover crop and a forage crop. It is grown principally in an area from Eastern and Northern Europe into Russia. It is much more tolerant of cold weather and poor soil than o ...

), pastures and roadsides, always on bare, nutrient‑rich soil. It may occur among grasses, herbs or mosses like '' Ceratodon purpureus'' and '' Brachythecium albicans''. Fruiting bodies appear from mid‑August to early November. The species is known from

hemiboreal Hemiboreal means halfway between the temperate and subarctic (or boreal) zones. The term is most frequently used in the context of climates and ecosystems. Botany A hemiboreal forest has some characteristics of a boreal forest to the north, an ...

to middle

boreal Boreal, northern, of the north. Derived from the name of the god of the north wind from Ancient Greek civilisation, Boreas (god), Boreas. It may also refer to: Climatology and geography *Boreal (age), the first climatic phase of the Blytt-Sernand ...

zones of southern Sweden and Finland, up to about 250 m elevation, but is generally regarded as rare.

References

{{Taxonbar, from=Q10455174 agrestis Fungi described in 1969 Fungi of Europe Poisonous fungi Fungus species