Toothed Crust Fungus

A toothed crust fungus, probably Radulomyces molaris, growing on the underside of a dead branch on a still-living oak tree (Quercus sp).

This is an older patch, dried out and cracked, from nearer the base of the branch.  It reminds me of the top of a lemon meringue pie.

And this is a younger patch, further away of the base of the branch.

I collected part of this patch and it yielded the following spores (shown at x600):

Given the image width of 86um these are about 8 x 5.5um, which is at the lower end of the range 8.3-11 x 5.5-7um given at Botany.cz.  (I think some of the spores in the above image might be pointing towards the viewer in which case my estimate of their longest dimension might be an under-estimate.)

First three photos taken in Whiteknights Park, Reading, UK, on 2012-12-23, 2012-12-18, and 2012-12-23, respectively.   The sample which produced the spores was collected from the same place on 2012-12-23.