Can anyone help identify this? It's grown out of my not-quite-mature compost that I spread around the new hamamelis. (Vegetarian tenant compost contributor has moved out, so can't ask him.) The colour is white/barely green, not the grey-white of Lumina. And no ridges on any of them. Most of them are perfectly globular, but you can see one is oblong-ish.

(Oops, can only upload one pic--I'll send second in following post.)

Ideas??