Small mushrooms called ink-caps belonging to the genus Coprinus (also seen as Coprinellus) are distinctive for a couple of reasons. At least one species from this group produces a conspicuous mycelial mat that is orange-brown, “fuzzy” and readily visible on surface of the substrate (usually dead wood). The mycelia of nearly all other mushrooms are entirely embedded in the substrate in which the mushroom occurs and if visible, appear as very fine white strands.
The caps may be brown, white or buff and establish on dead wood. They also may appear indoors, colonizing wood in moist environments like basements. The expanding mushroom fractures the veil leaving rows of tiny veil fragments on the cap while the white stipe elongates. Then, within a day or so the gills comprising most of the cap liquefy, forming a black, inky fluid which contains the spores and provides the mechanism for dispersing them. At this stage the mushroom looks nothing like the younger stage and might be mistaken for a different species.
The liquidification process is called deliquescence and some specialists have placed all deliquescent fungi in the genus Coprinus although there is not universal agreement on this. After the fruiting bodies are long gone, one or more new ones may appear on the same piece of wood and the distinctive mycelium may persist on the substrate for days, far outlasting individual mushrooms. The mushrooms themselves persist no longer than 3 or 4 days from first appearance until deliquescence.