''Crepidotus versutus'', commonly known as the evasive agaric, 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 th ...

in the family

Crepidotaceae The Crepidotaceae are a family of basidiomycete fungi. Taxonomic Details The Crepidotaceae have recently undergone a revision based on phylogenetic analyses. The following characters are typical of this family: * saprotrophic on woody or herbac ...

. It is saprobic on wood, like other ''

Crepidotus ''Crepidotus'' is a genus of fungi in the family Crepidotaceae. Species of ''Crepidotus'' all have small, convex to fan-shaped sessile caps and grow on wood or plant debris. The genus has been studied extensively, and monographs of the North Amer ...

'' species, but it can also decompose

herbaceous Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition of t ...

forest litter. The species is characterized by large, punctate,

ellipsoid An ellipsoid is a surface that may be obtained from a sphere by deforming it by means of directional scalings, or more generally, of an affine transformation. An ellipsoid is a quadric surface; that is, a surface that may be defined as the ...

spores, and the white, hairy pileus. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''versutus'' is derived from the

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 ...

word (clever), which may be a reference to the ability of the fungus to correctly orient itself for growth depending on the position of its growing surface. Google Books
/ref> The

basionym In the scientific name of organisms, basionym or basyonym means the original name on which a new name is based; the author citation of the new name should include the authors of the basionym in parentheses. The term "basionym" is used in both botan ...

of this species is ''Agaricus versutus'' Peck 1878. Older, obsolete synonyms include ''Crepidotus bresadolae'' and ''Crepidotus pubescens''.

Description

The pileus is typically 5–14 mm in diameter, initially

resupinate Resupination is derived from the Latin word ''resupinus'', meaning "bent back with the face upward" or "on the back". "Resupination" is the noun form of the adjective "resupine" which means "being upside-down, supine or facing upward". The word " ...

, then later turned up. It is attached dorsally or laterally to the substrate. Fan- or kidney-shaped, it is dry, white, and covered with a layer of soft hairs which may or may not be matted. The outer edge is rolled slightly inwards. The

context Context may refer to: * Context (language use), the relevant constraints of the communicative situation that influence language use, language variation, and discourse summary Computing * Context (computing), the virtual environment required to su ...

is thin, soft, and white. Both the odor and taste of this mushroom are mild. The gills radiate from an eccentric or lateral point of attachment, medium broad, and tend to swell in the middle. The gill spacing is sub-distant, with many short gills (lamellulae) that do not reach the attachment point. The gills are initially white, then later tinged a rusty-brown color. The spore print is cinnamon-brown in color. This species has no stipe, although it may have a small

tubercle In anatomy, a tubercle (literally 'small tuber', Latin for 'lump') is any round nodule, small eminence, or warty outgrowth found on external or internal organs of a plant or an animal. In plants A tubercle is generally a wart-like projection ...

attaching it to its growing surface.

Microscopic features

The basidiospores are 7–11 x 4.5–6

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 ...

in size, ellipsoid in shape, marked with very small spots, and yellowish to yellowish-brown under microscopic view. Basidia are 27–32 x 6–7 μm and 4-spored. Pleurocystidia are absent. The cheilocystidia are 22–63 x 3–12 μm, cylindric, and either swelling in the middle, or bottle-shaped. The gill trama are interwoven or at times subparallel, the

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 or ...

e 4–7 μm in diameter. The generative tissue below the hymenium (subhymenium) is arranged in a parallel fashion. The cuticle (the outer layer of the fruiting body) is made of dense interwoven hyphae, connected to a tuft of colorless, long, slender (2.5–5 μm diameter) hyphae. There are no clamp connections in the epicuticular hyphae, but there are on the hyphae of the tomentum at the base of the pileus. (Description adapted from Hesler & Smith, 1965Hesler LR, Smith AH. (1965). ''North American Species of Crepidotus''. Hafner Publishing Company: New York, NY. 168 p. + 18 pl.)

Habitat and distribution

This species may usually be found on the bark of

deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, aft ...

wood in damp, shaded places. In the

Pacific Northwest The Pacific Northwest (sometimes Cascadia, or simply abbreviated as PNW) is a geographic region in western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Though ...

, it is known to grow on ''

Abies Firs (''Abies'') are a genus of 48–56 species of evergreen coniferous trees in the family Pinaceae. They are found on mountains throughout much of North and Central America, Europe, Asia, and North Africa. The genus is most closely related to ...

'', '' Acer'' and ''

Populus ''Populus'' is a genus of 25–30 species of deciduous flowering plants in the family Salicaceae, native to most of the Northern Hemisphere. English names variously applied to different species include poplar (), aspen, and cottonwood. The we ...

'' trees.

Similar species

''Crepidotus applanatus'', the so-called "flat crep", is larger, with a shell-shaped cap, more closely spaced gills, and has conspicuous white

mycelia 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 in ...

l threads at the point of attachment. ''C. herbarum'' has smaller spores and a pale-yellowish spore print.

References

External links

Index Fungorum

* ttp://www.asturnatura.com/especie/crepidotus-versutus.html Photographs of microscopic structures, Spanish language {{Taxonbar, from=Q2090821 Crepidotaceae Fungi of North America Fungus species