I collected the following small specimen:
The underside was covered with pores, about 3 per mm:
The specimen only gave off a few small spores. These are shown in the following image (x600, image width about 86um).
These spores are about 4 x 1.5 um in size, which agrees well with the 3-6 x 1.5-2um given at MushroomExpert.com.
First photo taken and specimen collected in the Wilderness, Whiteknights Park, Reading, UK, on 2012-12-15.