A small cup fungus that forms fine dark speckling on the upper side of dead holly leaves. Initially the fruitbodies are greenish-brown and cushion shaped.   When they are mature a transparent lid opens to reveal the greenish-yellow fertile surface, or hymenium, from which the spores are eventually ejected.  A black crater about 1mm wide is left, embedded in the leaf tissue - these are the 'speckles' most often recorded.  

Phacidium lauri forms black pustules on dead Holly leaves, on both sides of the leaf, and is volcano-shaped; both species may occur together on the same leaf.  Similar species affect Ivy leaves (Trochila craterium) and Cherry Laurel (Trochila laurocerasi.)

Your photo should show the speckles in situ on the leaf and also in close-up. Check whether the speckles are on upper or lower side of the leaf, or both, and note this. Also note the substrate and associated tree species in your comments.

Only grows on dead (brown) leaves of holly

All year. The open lids are best seen December to February.

Widespread and fairly frequent in Britain.

Fairly frequent in Leicestershire and Rutland.