Inocybe lacera
Encyclopedia
Inocybe lacera is a poisonous
Mushroom poisoning
Mushroom poisoning refers to harmful effects from ingestion of toxic substances present in a mushroom. These symptoms can vary from slight gastrointestinal discomfort to death. The toxins present are secondary metabolites produced in specific biochemical pathways in the fungal cells...

 species of mushroom in the genus Inocybe
Inocybe
Inocybe is a large, complex genus of mushrooms. Members of Inocybe are mycorrhizal, and some evidence shows that the high degree of speciation in the genus is due to adaptation to different trees and perhaps even local environments.-Description:...

. Its appearance is that of a typical "little brown mushroom"; small, brown and indistinct. However, it is distinguishable by its microscopic features, particularly its long, smooth spores. As with many other species of Inocybe, I. lacera contains the poisonous chemical muscarine
Muscarine
Muscarine, L--muscarine, or muscarin is a natural product found in certain mushrooms, particularly in Inocybe and Clitocybe species, such as the deadly C. dealbata. Mushrooms in the genera Entoloma and Mycena have also been found to contain levels of muscarine which can be dangerous if ingested...

 which, if consumed, can lead to salivation, lacrimation, urination
Urination
Urination, also known as micturition, voiding, peeing, weeing, pissing, and more rarely, emiction, is the ejection of urine from the urinary bladder through the urethra to the outside of the body. In healthy humans the process of urination is under voluntary control...

, defecation
Defecation
Defecation is the final act of digestion by which organisms eliminate solid, semisolid or liquid waste material from the digestive tract via the anus. Waves of muscular contraction known as peristalsis in the walls of the colon move fecal matter through the digestive tract towards the rectum...

, gastrointestinal problems and emesis. Found in Europe and North America, it typically grows in autumn in mixed woods, favouring sandy soil. There are several documented subspecies in addition to the main I. lacera var lacera, including the dwarf form I. lacera var. subsquarrosa and I. lacera var. heterosperma, found in North America.

Taxonomy

Inocybe lacera was first described by Swedish mycologist
Mycology
Mycology is the branch of biology concerned with the study of fungi, including their genetic and biochemical properties, their taxonomy and their use to humans as a source for tinder, medicinals , food and entheogens, as well as their dangers, such as poisoning or...

 Elias Magnus Fries
Elias Magnus Fries
-External links:*, Authors of fungal names, Mushroom, the Journal of Wild Mushrooming.*...

, but was placed into the genus Inocybe by Paul Kummer
Paul Kummer
Paul Kummer was a priest, teacher, and scientist in Zerbst, Germany, known chiefly for his contribution to mycological nomenclature. Earlier classification of agarics by pioneering fungal taxonomist Elias Magnus Fries designated only a very small number of genera, with most species falling into...

 in his 1871 work, Der Führer in die Pilzkunde. As several forms of the species are recognised, the main variety is sometimes known as Inocybe lacera var. lacera. It is commonly known
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...

 as the Torn Fibrecap, while in German it is known as Gemeiner Wirrkopf and in French as Inocybe déchiré.

Description

In appearance, I. lacera is a typical "little brown mushroom", but specific features are very variable. It typically features a convex cap
Pileus (mycology)
The pileus is the technical name for the cap, or cap-like part, of a basidiocarp or ascocarp that supports a spore-bearing surface, the hymenium. The hymenium may consist of lamellae, tubes, or teeth, on the underside of the pileus...

 measuring 1 to 3 cm (0.393700787401575 to 1.2 in) across, with a small umbo. The margin of the cap curves inwards, and often splits. In colour, it is snuff
Snuff
Snuff is a product made from ground or pulverised tobacco leaves. It is an example of smokeless tobacco. It originated in the Americas and was in common use in Europe by the 17th century...

-brown, and in consistency, it is fibrillose and scaley. The stipe, or stem
Stipe (mycology)
thumb|150px|right|Diagram of a [[basidiomycete]] stipe with an [[annulus |annulus]] and [[volva |volva]]In mycology a stipe refers to the stem or stalk-like feature supporting the cap of a mushroom. Like all tissues of the mushroom other than the hymenium, the stipe is composed of sterile hyphal...

, is 2 to 3 cm (0.78740157480315 to 1.2 in) tall, and 3 to 6 mm (0.118110236220472 to 0.236220472440945 in) thick, brown at the slightly bulbous base, but lighter towards the apex, and, again, fibrillose. The stem lacks a ring. The flesh
Trama (mycology)
In mycology trama is a term for the inner, fleshy portion of a mushroom's basidiocarp, or fruit body. It is distinct from the outer layer of tissue, known as the pileipellis or cuticle, and from the spore-bearing tissue layer known as the hymenium....

 is white. The adnexed gills are white in younger specimens, soon changing to a clay-buff with white edges.

Microscopic features

Inocybe lacera has thick-walled, fusiform cystidia, which have apical encrustations. It has a brown spore print
Spore print
thumb|300px|right|Making a spore print of the mushroom Volvariella volvacea shown in composite: mushroom cap laid on white and dark paper; cap removed after 24 hours showing pinkish-tan spore print...

, while the subcylindrical spore
Spore
In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa. According to scientist Dr...

s are smooth, typically measuring 11 to 15 by 4.5 to 6 µm
Micrometer
A micrometer , sometimes known as a micrometer screw gauge, is a device incorporating a calibrated screw used widely for precise measurement of small distances in mechanical engineering and machining as well as most mechanical trades, along with other metrological instruments such as dial, vernier,...

 in size. I. lacera is one of a small group of related species with particularly long, cylindrical spores, the others of which can typically be found on sand dunes. The spore shape is more typical of species from the order Boletales
Boletales
The Boletales are an order of Agaricomycetes, containing over 1300 species with a diverse array of fruiting body types. The boletes are the best known members of this group, and until recently, the Boletales were thought to only contain boletes...

. These features make the I. lacera easily recognisable microscopically. The "dwarf form", I. lacera var. subsquarrosa, has small spores and thin-walled cystidia, while a North American variant, I. lacera var. heterosperma has spores varying from 5.5 to 15.5 µm in length. The species has 4-spored basidia.

Similar species

Inocybe hystrix
Inocybe hystrix
Inocybe hystrix is an agaric which forms mycorrhiza with surrounding deciduous trees. It is usually found growing alone or in small groups on leaf litter during autumn months. Unlike many Inocybe species, Inocybe hystrix is densely covered in brown scales, a characteristic that aids in identification...

is similar in appearance, but noticeably more scaly. It is also far less common.

Edibility

Inocybe lacera has mild-tasting flesh and a mild, mealy smell. The North American variety I. lacera var. heterosperma has a spermatic smell. However, species of Inocybe
Inocybe
Inocybe is a large, complex genus of mushrooms. Members of Inocybe are mycorrhizal, and some evidence shows that the high degree of speciation in the genus is due to adaptation to different trees and perhaps even local environments.-Description:...

should always be avoided when choosing mushrooms for consumption, as many of the members of the genus are dangerously toxic. I. lacera is known to be poisonous, containing quantities of the toxic compound muscarine
Muscarine
Muscarine, L--muscarine, or muscarin is a natural product found in certain mushrooms, particularly in Inocybe and Clitocybe species, such as the deadly C. dealbata. Mushrooms in the genera Entoloma and Mycena have also been found to contain levels of muscarine which can be dangerous if ingested...

. Consumption of the mushroom typically leads to salivation, lacrimation, urination
Urination
Urination, also known as micturition, voiding, peeing, weeing, pissing, and more rarely, emiction, is the ejection of urine from the urinary bladder through the urethra to the outside of the body. In healthy humans the process of urination is under voluntary control...

, defecation
Defecation
Defecation is the final act of digestion by which organisms eliminate solid, semisolid or liquid waste material from the digestive tract via the anus. Waves of muscular contraction known as peristalsis in the walls of the colon move fecal matter through the digestive tract towards the rectum...

, gastrointestinal problems and emesis (vomiting), which has given rise to the acronym SLUDGE. Other potential effects include a drop in blood pressure
Blood pressure
Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...

, sweating
Sweating
Perspiration is the production of a fluid consisting primarily of water as well as various dissolved solids , that is excreted by the sweat glands in the skin of mammals...

 and death due respiratory failure
Respiratory failure
The term respiratory failure, in medicine, is used to describe inadequate gas exchange by the respiratory system, with the result that arterial oxygen and/or carbon dioxide levels cannot be maintained within their normal ranges. A drop in blood oxygenation is known as hypoxemia; a rise in arterial...

.

Distribution and habitat

Inocybe lacera can be found throughout autumn on sandy soil, especially with pine, though it is typically found in mixed woods. It grows mycorrhizally with both conifers and hardwoods, and the fruiting bodies can be found alone, in scattered groups, or growing gregariously. It is most commonly found on the edge of pathways through woodland, and another common habitat is on old, moss-covered fire sites. Other habitats include heathland and coastal dunes. It can be found in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

 and North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

. In some areas of Montana
Montana
Montana is a state in the Western United States. The western third of Montana contains numerous mountain ranges. Smaller, "island ranges" are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...

, it can be found growing in the spring, under Populus tremuloides
Populus tremuloides
Populus tremuloides is a deciduous tree native to cooler areas of North America, commonly called quaking aspen, trembling aspen, American aspen, and Quakies,. The trees have tall trunks, up to 25 metres, with smooth pale bark, scarred with black. The glossy green leaves, dull beneath, become golden...

.
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