''Cortinarius traganus'', also known as the gassy webcap or lilac conifer cortinarius, is a

basidiomycete Basidiomycota () is one of two large divisions that, together with the Ascomycota, constitute the subkingdom Dikarya (often referred to as the "higher fungi") within the kingdom Fungi. Members are known as basidiomycetes. More specifically, Basi ...

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 ...

of the genus ''

Cortinarius ''Cortinarius'' is a globally distributed genus of mushrooms in the family Cortinariaceae. It is suspected to be the largest genus of agarics, containing over 2,000 widespread species. A common feature among all species in the genus ''Cortinari ...

''. The mushrooms are characterized by their lilac color, the rusty-brown

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 ...

and

spore In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, ...

s, and rusty-brown

flesh Flesh is any aggregation of soft tissues of an organism. Various multicellular organisms have soft tissues that may be called "flesh". In mammals, including humans, ''flesh'' encompasses muscles, fats and other loose connective tissues, but ...

in the

stem Stem or STEM may refer to: Plant structures * Plant stem, a plant's aboveground axis, made of vascular tissue, off which leaves and flowers hang * Stipe (botany), a stalk to support some other structure * Stipe (mycology), the stem of a mushr ...

Taxonomy

The species was originally named ''Agaricus traganus'' by Elias Magnus Fries. It is commonly known as the "gassy webcap" the "lilac conifer Cortinarius", or the "pungent Cort". Some authorities consider the American variant to be a distinct species, ''Cortinarius pyriodorus'', reserving the name ''C. traganus'' for the European version.

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 in diameter, initially spherical to convex, with the margin rolled inward, then flattened, sometimes with large, broad, central umbo. The margin often cracks star-like, particularly in dry weather. The mushroom is a pale azure violet to pale lilac color, soon bleaching and fading to tan brown or rusty brown. The cap is dry, silkily shiny or tomentose at the margin with membranaceous bronze fragments of the

veil A veil is an article of clothing or hanging cloth that is intended to cover some part of the head or face, or an object of some significance. Veiling has a long history in European, Asian, and African societies. The practice has been prominent ...

, the white fragments of which often adhere to the surface like scabs. Later the surface becomes cracked into small scales. The

are sub-crowded, quite thick, broadly adnate, and often slightly emarginate (notched). They are broad, slightly dirty violet when young but usually brown, with only faintly violet tint, later brown, dusted saffron ochre, and with lighter crenulate edge. The

is long and thick, tough and thick, bulbously at the base, and spongily stuffed inside. It is vivid violet for a long time in the upper part above the cortina, paler below, and covered with a tough, whitish, boot-like veil, which usually leaves upright zones on the stem. The cortina is violet. The

is saffron yellowish-brown to yellowish-brown from the beginning except at the tip of the stem where it is dirty violaceous, or, unpleasantly, goats, so much so that it may induce vomiting in more sensitive individuals. It has a strong, bitter taste, particularly when young. 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- ...

(the

-bearing cells) are 30–35 by 6.5–7.5

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 Uni ...

. The

spore deposit 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 ...

is rusty brown. The spores are

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 ...

, covered with fine warts or dots, and measure 8–9 by 5–5.5 μm.

Similar species

Cortinarius camphoratus ''Cortinarius camphoratus'', commonly known as the goatcheese webcap, is an agaric fungus in the family Cortinariaceae. The fungus is found in Europe and North America, where its fruit bodies (mushrooms) grow on the ground in a mycorrhizal assoc ...

'' is similar in appearance and is also violet, but it has pale violet gills which soon turn rusty, and a longer stem with paling flesh at the base. Its spores are also longer, warty, and measure 8.5–11 by 5–6 μm. It has a pungent smell, somewhat different from that of ''C. traganus''—similar to rotting potatoes. Another lookalike species is ''

Cortinarius muricinus ''Cortinarius'' is a globally distributed genus of mushrooms in the family Cortinariaceae. It is suspected to be the largest genus of agarics, containing over 2,000 widespread species. A common feature among all species in the genus ''Cortinari ...

'' with the cap either permanently violet or becoming rust-colored from the disc outward. The gills are initially blue, dirty cinnamon when old, and the stem violet lilac, with lighter fragments of the veil later turning rust-colored. Its spores measure 13–15 by 7–8 μm.

Edibility

The mushroom has been variously reported as "mildly poisonous", or indigestible. It should not be consumed due to its similarity to deadly poisonous species.

Distribution and habitat

''Cortinarius traganus'' is a widespread species that is found in

coniferous forest Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All ex ...

s worldwide. It seems to prefer poorer soils, both

siliceous Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is ...

and non-

calcareous Calcareous () is an adjective meaning "mostly or partly composed of calcium carbonate", in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines. In zoology ''Calcareous'' is used as an a ...

. It grows throughout the

temperate In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout t ...

zone of the northern hemisphere.

References