Cystolepiota bucknallii

Cystolepiota bucknallii
Scientific classification
Kingdom:	Fungi
Phylum:	Basidiomycota
Class:	Agaricomycetes
Order:	Agaricales
Family:	Agaricaceae
Genus:	Cystolepiota
Species:	C. bucknallii
Binomial name
Cystolepiota bucknallii (Berk. & Broome) Singer & Clémençon (1972)
Synonyms
Agaricus bucknallii Cystoderma bucknallii Cystolepiota bucknallii var. lilacina Lepiota bucknallii Lepiota lilacina Lepiota seminuda var. lilacina[1]

Cystolepiota bucknallii
Mycological characteristics
	gills on hymenium
	cap is convex
	hymenium is free
	stipe is bare
	spore print is white
	ecology is saprotrophic
	edibility: inedible

Cystolepiota bucknallii is a species of basidiomycete fungus of the genus Cystolepiota. Found throughout Europe, it is a rare fungus occurring in deciduous forests. The small fruiting bodies bear a distinctive smell of coal gas and appear in autumn on damp ground. It is not an edible mushroom.

Description

The fruiting body of Cystolepiota bucknallii is a relatively small, thin-fleshed agaric. The cap is at first hemispherical and becomes convex with maturity. It bears a broad central umbo and reaches 5 cm in diameter. The cap cuticle is white with a lilac or violet tinge. The gills are crowded and not attached to the stem. Their colour is cream to pale yellow. The stem is comparatively long (up to 6 cm), slender and bare, tinged lilac or violet except for the uppermost section where it is pallid. Both cap and stem are covered with a mealy powder which is easily rubbed off. All parts are fragile. The flesh is white, thin and does not bear a distinctive taste.^[2][3]

The spore mass is coloured white. With the aid of a light microscope, the spores are seen ellipsoid, smooth and colourless. When Melzer's reagent is applied, the spore walls barely stain; hence, the spores are weakly dextrinoid. Their dimensions are 7.5–10 µm by 1-3.5 µm.^[2][3]

C. bucknallii has a characterisitcally pungent odour, reminiscent of coal gas or sulphur. Indole is present in this as well as in other similar-scented fungi: Tricholoma inamoenum, Tricholoma lascivum, Tricholoma sulphureum and others.^[4]

While its edibility is not known, there exists speculation about possible toxicity.^[2][3]

Habitat

C. bucknallii has been recorded in various countries in central and northern Europe including France, Belgium, Switzerland, Austria, Germany, Denmark, Norway, Sweden and Russia.^[5] It is a terrestrial decomposer which occurs in deciduous forests with moist, calcareous soils rich in nutrients and especially nitrogen. Fruiting bodies appear in autumn.^[3] Moreover, C. bucknallii is an uncommon or rare fungus whose populations are found in communities harbouring a diversity of other rare species. A population may serve as an indicator for rich, conservable biotopes.^[6]

External links

• Images of C. bucknallii at BioImages (UK)

References

1. ^ "Cystolepiota bucknallii taxon record details at Index Fungorum". CAB International. http://www.indexfungorum.org/Names/SynSpecies.asp?RecordID=312540. Retrieved February 2, 2010. 
2. ^ ^{a b c} "Cystolepiota bucknallii at Rogers Mushrooms". Rogers Plants Ltd. http://www.rogersmushrooms.com/gallery/DisplayBlock~bid~6294~gid~.asp. Retrieved December 13, 2009. 
3. ^ ^{a b c d} Jordan M. (1995). The Encyclopedia of Fungi of Britain and Europe. London: David & Charles. p. 215. ISBN 0-7153-0129-2. 
4. ^ Wood W., Smith J., Wayman K., Largent D. (2003). "Indole and 3-chloroindole: The source of the disagreeable odor of Hygrophorus paupertinus". Mycologia 95 (5): 807–08. doi:10.2307/3762008. JSTOR 3762008. 
5. ^ "Cystolepiota bucknallii - GBIF Portal". GBIF. http://data.gbif.org/species/14373174. Retrieved 2 February 2010. 
6. ^ "Factsheet: Cystolepiota bucknallii – violettfotad puderskivling" (in Swedish). ArtDatabanken. http://www.artdata.slu.se/rodlista/Faktablad/cys_buck.PDF. Retrieved February 2, 2010. ^{[dead link]}