Shaggy ink cap Coprinus comatus fungus growing in leaf litter on a forest floor. This is a common mushroom and when young is considered fine eating. It takes its name from the behaviour of the cap when mature or when it is cut: over time the gills and cap deliquesce, turning into a dark liquid. It is inedible at this stage, so must be harvested young and cooked within a few hours. Filmed in Denmark.