Coprinellus domesticus (Bolton) Vilgalys, Hopple & Jacq. Johnson - Firerug Inkcap

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

Coprinellus domesticus

Similar to the Fairy Inkcap (also known as the Trooping Inkcap) Coprinellus disseminatus, but larger and often with an orange shaggy carpet, known as 'ozonium', growing on the surface of the substrate around the stem bases, the Firerug Inkcap is one of several similar species that require careful study to confirm their identities. The ozonium is a very helpful clue, but it is not always present; however, ozonium is much longer lasting that the inkcap fruitbodies, and so it is often found where there is no evidence of the mushrooms themselves.

Ozonium, New Forest UK


A fairly common find in most parts of Britain and Ireland, this inkcap occurs throughout most of mainland Europe and is also recorded in parts of North America.

Taxonomic history

This inkcap mushroom was first described scientifically in 1788 by English botanist James Bolton (1750 - 1799), who gave it the name Agaricus domesticus. Following DNA studies of the former Coprinus group, this species was transferred to the genus Coprinellus in 2001 by American mycologists Rytas J. Vilgalys, John Hopple and Jacques Johnson.

Synonyms of Coprinellus domesticus include Agaricus domesticus Bolton, and Coprinus domesticus (Bolton) Gray.


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. The suffix -ellus indicates fungi that produce fruitbodies that are rather smaller than fruitbodies of Coprinus species. The specific epithet domesticus comes directly from the Latin domus meaning a house or a home, reflecting the fact that this mushroom sometimes appears on damp flooring or roof timbers. The common name Firerug inkcap refers to the shaggy rug-like orange 'ozinium' that sometimes appears on the substrate from which this inkcap emerges.

Identification guide

Cap of Coprinellus domesticus


3 to 7cm across, initially oval becoming convex and finally broadly bell-shaped with a lined margin ; honey-ochre with a slightly darker centre; covered with whitish to pale brown sand-like veil fragments; turning grey when old but not deliquescing.

Gills and stem of Coprinellus domesticus


Adnexed or free; crowded; creamy-white, turning grey then blackish and deliquescing.


4 to 10cm long and 0.4 to 1cm diameter with a slightly swollen base; white; silky smooth; hollow, no stem ring.

Spore of Coprinellus domesticus


Ellipsoidal, smooth, 6-9 x 3.5-5µm; with an eccentric germ pore.

Show larger image

Spore print

Very dark brown, almost black.


Not distinctive.

Habitat & Ecological role

Saprobic, appearing sometimes singly but more often in small groups on decaying hardwood.


June to November.

Similar species

The Glistening Inkcap, Coprinellus micaceus, is of similar size and colouring. The spores of Coprinellus domesticus.are noticeably smaller than those of Coprinellus micaceus (which are 7-10 x 4.5-6µm) and they also have a larger Q value (length to diameter ratio).

Culinary Notes

Coprinellus domesticus is of no cullinary interest.

Reference Sources

Fascinated by Fungi, 2nd Edition, Pat O'Reilly 2016, reprinted by Coch-y-bonddu Books in 2022.

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.

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.

Top of page...

Fascinated by Fungi, 2nd edn, hardback

Fascinated by Fungi. Back by popular demand, Pat O'Reilly's best-selling 450-page hardback book is available now. The latest second edition was republished with a sparkling new cover design in September 2022 by Coch-y-Bonddu Books. Full details and copies are available from the publisher's online bookshop...

© 1995 - 2024 First Nature: a not-for-profit volunteer-run resource

Please help to keep this free resource online...

Terms of use - Privacy policy - Disable cookies - Links policy