The substrate is a branch of wild cherrywood that had been lying on the ground for a year, with these structures on the underside
only a few of the balls were stalked; most were sessile, and some a lot smaller.
The color originally was purplish, as in the first image. some aged to this reddish shade later. The scale in the background is in centimeters
Surface close up
Some of the balls started showing surface structures like this. I'd just finished hatching out 100 solitary wasps from a large gall on a wild rosebush root, so thought at first that this might also have been a gall of some sort
A cross section of the ball from the third picture (centimeter/millimeter scale in background
I don't have a good photographing setup for photo microscopy, so apologies for the fuzzy picture. I had put one of the balls in a closed container to see if anything would hatch out. Instead I got a black sooty spore deposit. Guess that the spores rule out insects .
Size is about 13 by 6 microns.