Clitocybe

Clitocybe is a genus of mushrooms characterized by white, off-white, buff, cream, pink, or light-yellow spores, gills running down the stem, and pale white to brown or lilac coloration. They are primarily saprotrophic, decomposing forest ground litter. There are estimated to be around 300 species in the widespread genus.

Clitocybe means sloping head.

A few members of the genus are considered edible; many others are poisonous, containing the toxin muscarine among others. Distinguishing individual species of Clitocybe is generally prohibitively difficult to non-experts, requiring the analysis of microscopic characters. Therefore, with the exception of a few charismatic and readily identified members, Clitocybe mushrooms are rarely collected for consumption.

Taxonomy
Clitocybe was originally proposed by Elias Fries in 1821 as a tribe in the genus Agaricus. Friedrich Staude elevated it to generic status in 1857.

Recent molecular work has shown the genus to be polyphyletic: many members are seemingly distantly related and other fungi, such as the field blewit and wood blewit, now known as Clitocybe saeva and C. nuda respectively, are more closely related.

As C. nebularis is the type species, those most distantly related to it would be likely to be reclassified in the future. In a 2003 paper, Finnish mycologist Harri Harmaja proposed C. geotropa and twelve other Clitocybe species be split off into a new genus Infundibulicybe on the basis of spore properties. His C. clavipes was later transferred to the genus Ampulloclitocybe by Redhead and colleagues, that genus name taking precedence over Harmaja's proposed Clavicybe. Other former Clitocybe species have been placed in the genera Atractosporocybe, Leucocybe and Rhizocybe.

Toxicity
The consumption of two species, Clitocybe acromelalga from Japan, and Clitocybe amoenolens from France, has led to several cases of mushroom-induced erythromelalgia which lasted from 8 days to 5 months.



Many small Clitocybe species contain the toxin muscarine, which was originally found in small amounts in the famous fly agaric. However, the small white Clitocybe species contain muscarine in dangerous amounts, and two species in particular, the closely related Clitocybe dealbata and Clitocybe rivulosa, contain muscarine in such amounts that deaths have been recorded for eating those two Clitocybe species.

Selected species

 * Clitocybe agrestis
 * Clitocybe albirhiza
 * Clitocybe amarescens
 * Clitocybe brumalis – winter funnel cap
 * Clitocybe cerussata
 * Clitocybe cistophila – Europe
 * Clitocybe costata – may be edible but due to its rareness it is not consumed.
 * Clitocybe dealbata – ivory funnel, sweating mushroom – Europe, poisonous
 * Clitocybe dilatata – poisonous
 * Clitocybe ditopus
 * Clitocybe eccentrica
 * Clitocybe entoloma
 * Clitocybe eucalyptorum
 * Clitocybe fennica
 * Clitocybe fragrans – fragrant funnel
 * Clitocybe gilvaoides
 * Clitocybe glacialis
 * Clitocybe globispora
 * Clitocybe glutiniceps
 * Clitocybe lohjaensis
 * Clitocybe marginella
 * Clitocybe menthiodora
 * Clitocybe nebularis – clouded agaric – considered edible by some, though causes gastric upset in many people


 * Clitocybe odora – aniseed toadstool – grows near birch trees, but can be easily mistaken for poisonous ones mainly because of its appearance
 * Clitocybe paraditopa – Australia
 * Clitocybe parasitica
 * Clitocybe rivulosa – fool's funnel – Europe, North America
 * Clitocybe ruderalis
 * Clitocybe sclerotoidea
 * Clitocybe strigosa
 * Clitocybe subcordispora
 * Clitocybe tarda
 * Clitocybe truncicola
 * Clitocybe vibecina
 * Clitocybe violaceifolia

Taxonomic status unclear

 * Clitocybe maxima – giant clitocybe – taxonomic status unclear, with Pleurotus giganteus and Infundibulicybe hongyinpan mistaken for this species

Reclassified
The bioluminescent jack o'lantern mushroom (Omphalotus olearius) was formerly placed in this genus as Clitocybe illudens.
 * Clitocybe acromelalga – now Paralepistopsis acromelalga
 * Clitocybe alexandri – now Clitopaxillus alexandri
 * Clitocybe amoenolens – paralysis funnel – now Paralepistopsis amoenolens
 * Clitocybe brunneocephala – now Collybia brunneocephala – edible
 * Clitocybe nuda – Lepista nuda – Collybia nuda – wood blewit – a common edible distinguished in part by its lilac hue
 * Clitocybe candicans – now Leucocybe candicans
 * Clitocybe catinus / Infundibulicibe catinus – a white form of Infundibulicybe gibba
 * Clitocybe clavipes – may be edible but poisonous when consumed in conjunction with alcohol – now Ampulloclitocybe clavipes
 * Clitocybe connata – inedible, suspected to be mutagenic – now Leucocybe connata
 * Clitocybe geotropa – trooping funnel, monk's head agaric – now Infundibulicybe geotropa
 * Clitocybe gibba – now Infundibulicybe gibba