Translated from a report by the Dutch Mycological Society on Wednesday, August 11, 2010:
Recently, in a ditch along a heavily fertilized corn field, an ascomycte species new for the Netherlands has been found. The new species, Calycellina spiraeae, is very small and not easily recognizable as a mushroom. Moreover, maize fields are often regarded as places where nothing special is to be found.
Many ascomycete fungi are very small and grow on a specific substrates such as leaves or wood of a particular tree, shrub or plant. On Sunday, July 25, a species, new for the Netherlands, was found on the dead leaves of Meadowsweet (Filipendula ulmaria) growing in a ditch along a corn field.
See also here.
The discovery was near Boxmeer. More photos are here.