Kingdom: Fungi
Division: Basidiomycota
Class: Agaricomycetes
Order: Agaricales
Family: Psathyrellaceae
Genus: Coprinopsis
Species: C. spelaiophila
Binomial name: Coprinopsis spelaiophila
Synonyms: Coprinus extinctorius, Coprinus spelaiophilus, Coprinopsis extinctoria.
Common name: Inkcap, Ink cap.

Coprinopsis spelaiophila is a small, delicate, deliquescing mushroom of the Coprinopsis genus which members have a whitish cap and a white stem. This a type of mushroom that is called an inkcap because when the spores are shed the depleted gills dissolve (auto-digest) first into a clear liquid then into a black fluid containing the black spores. When all the spores are shed only a black stained stalk remains. Coprinopsis spelaiophila is 'distinctive' because of the big tufts of veil remnants on the cap. The scales on the cap age quickly to become dark in the cap centre.
They are usually found inside hollow trees on rotting wood... The scales on the cap age quickly to become dark in the cap centre, so seeing a pure white cap is in itself unusual.

Coprinopsis spelaiophila.JPG

Coprinopsis spelaiophila-001.JPG

Coprinopsis spelaiophila-003.JPG

Photo shows the start of the gills dissolving (auto-digest).
Coprinopsis spelaiophila-001.JPG

Coprinopsis spelaiophila-002.JPG

Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0/