Coprinellus disseminatus (Pers.) J.E. Lange - Fairy Inkcap

Phylum: Basidiomycota - Class: Agaricomycetes - Order: Agaricales - Family: Psathyrellaceae

Coprinellus disseminatus - Fairy Inkcaps on the stump of a dead tree

The Fairy Inkcap, Coprinellus disseminatus, rarely ventures forth alone or even with just a few friends; more often it forms dense masses swarming over rotting tree stumps and roots.

These gregarious little fungi occur from early spring until the onset of winter, and they are at their most spectacular when the caps are young and pale - sometimes nearly pure white. It takes just two or three days for young white caps to turn grey and then begin blackening.

Distribution

Common in Britain and Ireland and throughout Europe and North America, the Fairy Inkcap is truly a cosmopolitan mushroom, being found also in most parts of Asia and in South America and Australia. Coprinellus disseminatus usually appears in very large trooping groups on stumps in woodland and occasionally in shaded hedgerows.

Coprinellus disseminatus - Fairy Inkcaps, young fruitbodies

Taxonomic history

Originally described by Christiaan Hendrik Persoon, the Fairy Inkcap was given its present scientific name in 1939 by the Danish mycologist Jakob Emanuel Lange (1864–1941). In many field guides this species is still recorded as Coprinus disseminatus, under which name it was commonly - Classified until 2001.

Synonyms of Coprinellus disseminatus include Agaricus minutulus Schaeff., Agaricus disseminatus Pers., Coprinus disseminatus (Pers.) Gray, Coprinarius disseminatus (Pers.) P. Kumm., and Pseudocoprinus disseminatus (Pers.) Kuhner.

Because it does not autodigest (deliquesce), some authors have placed this species in the genus Pseudocoprinellus rather than in Coprinellus. Hence Pseudocoprinellus disseminatus (Pers.) Kuhner is a synonym.

Other common names for these lovely little mushrooms include Fairies Bonnets (a name likely to cause confusion with Mycena species, which are often referred to as Bonnets or Bonnet Caps) and Trooping Inkcaps.

Common names change with time and location. In America the terms Inky Cap or Inky-cap are most commonly used, while in many older field guides published in Britain you are likely to see Ink Cap or Ink-cap rather than Inkcap.

Another common name given to this species in Trooping Crumble-cap, reflecting their tendency to dinsintegrate when touched; this, with their diminutive stature, is another reason not to try gathering Fairy Inkcaps to take home to cook.

Coprinellus disseminatus - Fairy Inkcaps, older fruitbodies

Etymology

The generic name Coprinellus indicates that this mushrooms genus is (or was thought to be) closely related to or at least similar to fungi in the genus Coprinus, which literally means 'living on dung' - that's true of quite a few of the inkcaps but not particularly apt for this and several other Coprinellus species that feed on rotting timber. Coprinellus disseminatus is a vegetarian that does not like 'second hand' food that has already passed through the gut of an animal. The suffix -ellus indicates fungi that produce rather smaller fruitbodies than those of Coprinus species. The specific epithet disseminatus is the past participle of the Latin verb disseminare, formed from the prefix dis-, meaning 'in all directions' (as in display, disintegrate etc) and seminare, meaning 'to plant' or' to propagate' (as in semen, from which is derived the English word seed). Appropriate for these prolific fungal hordes!

The Fairy Inkcaps shown here are the same group that is pictured above but photographed on the following day. The change in cap shape and colour in such a short time is already quite remarkable.

Identification guide

Cap of Coprinellus disseminatus

Cap

Typically 0.5 to 1.5cm in diameter and initially 1 to 1.5cm tall, flattening as they open out, the caps of Coprinellus disseminatus are at first egg-shaped, then bell-shaped often with slightly upturned margins.

Beige when young, the pleated caps turn grey and then blacken somewhat from the margin.

Gills of Coprinellus disseminatus

Gills

The adnate gills of Coprinellus disseminatus are white, turning grey and then black as the spores mature. When fully mature they do not dissolve rapidly into an inky fluid, as many of the ink caps do.

Stem

The thin, hollows stems of the Fairy Inkcap are white and very fragile.

Spores of Coprinellus disseminatus

Spores

Ellipsoidal to almond-shaped, smooth; 7-9.5 x 4-5µm; with an apical germ pore.

Show larger image

Spore print

Black.

Odour/taste

Not distinctive.

Habitat & Ecological role

Coprinellus disseminatus is saprobic and occurs on and beside stumps and other forms of rotting wood.

Season

August to November in Britain.

Similar species

Coprinellus micaceus grows in tufts, but rarely in such massive groups; it has larger, tan caps which are covered in tiny glistening veil fragments when young.

Coprinellus disseminatus - Fairy Inkcaps on buried roots, Cambridgeshire, England

Culinary Notes

The Fairy Inkcap is reported to be edible, but it is insubstantial and not highly regarded.

Reference Sources

Fascinated by Fungi, Pat O'Reilly 2016.

Orton, P.D. & Watling, R. (1979). British Fungus Flora: Agarics and Boleti. Vol 2. Coprinaceae: Coprinus. Royal Botanic Garden: Edinburgh.

Redhead SA, Vilgalys R, Moncalvo J-M, Johnson J, Hopple JS Jr.; Vilgalys, Rytas; Moncalvo, Jean-Marc; Johnson, Jacqui; Hopple, Jr. John S (2001). 'Coprinus Pers. and the disposition of Coprinus species sensu lato.'. Taxon (International Association for Plant Taxonomy (IAPT)) 50 (1): 203-41.

Coprinellus disseminatus, Fairy Inkcaps on buried roots, a new swarm arising

English Names for fungi; British Mycological Society, 2013.

Dictionary of the Fungi; Paul M. Kirk, Paul F. Cannon, David W. Minter and J. A. Stalpers; CABI, 2008

Taxonomic history and synonym information on these pages is drawn from many sources but in particular from the British Mycological Society's GB Checklist of Fungi and (for basidiomycetes) on Kew's Checklist of the British & Irish Basidiomycota.

Above: Fairy Inkcaps emerging as a swarm of pallid mushrooms in a dark woodland setting.

Other web pages about this species

Nature Spot (UK)

Michael Wood & Fred Stevens (USA)

Top of page...


Pat O'Reilly

If you have found this information helpful, we are sure you would also find our book Fascinated by Fungi by Pat O'Reilly very useful. Author-signed hardback copies at a special discount price are available here...

Other nature books from First Nature...