Macrocybe

Macrocybe is a genus of fungi in the family Tricholomataceae. The genus contains seven species, widely distributed in tropical regions worldwide.[1]

Macrocybe
unidentified Macrocybe species
Scientific classification
Kingdom:	Fungi
Division:	Basidiomycota
Class:	Agaricomycetes
Order:	Agaricales
Family:	Tricholomataceae
Genus:	Macrocybe Pegler & Lodge (1998)
Type species
Macrocybe titans (H.E.Bigelow & Kimbr.) Pegler, Lodge & Nakasone (1998)
Species
M. crassa M. gigantea M. lobayensis M. pachymeres M. praegrandis M. spectabilis M. titans

The genus was established in 1998 by mycologists David Pegler and Deborah Jean Lodge, for several large white tropical species that had been placed in the genus Tricholoma.[2] The name is derived from the Ancient Greek words makros "long" and kube "head". The genus is related to the genus Calocybe.[2]

The species form huge pale fleshy mushrooms that often grow in clumps on dead wood in the ground. The weight of the cluster may exceed 30 kg.[2] The caps are convex to depressed, and sometimes have a central boss (umbo), and are white to cream or pale ochre or grey. One species, M. titans, has a cap that can reach a metre (40 in) in diameter. The white gills are sinuate. The flesh is white and does not change colour when bruised. The stipe is white and often has a swollen base. The spore print is white. The round to oval spores are less than 10 micrometres long and smooth.[2]

The species are saprobic, growing on dead wood in grass generally.[2] One species, M. gigantea, has been found growing on elephant dung in Kerala state in India,[3] and M. crassa has been cultivated on horse manure in Thailand.[2]

Some species have tasty mushrooms, which are eaten in the tropics.[2] An undescribed species is eaten by the Patamona people in Guyana.[4] Although edible, some species do contain traces of cyanide that require cooking to eliminate.[2]