In nature nothing is wasted and not least vegetable matter. These nice three species are all findable on fallen Birch leaves at the moment
Left is Discosia artocreas, centre is Gnomonia alni-viridis (syn. setacea) and right is Venturia ditricha.
The Discosia is nice under the lens, with spores which have appendages and whose ends are entertainingly cyanophilous
These are all from Calis Muir Wood in Dunfermline