I think these are the spore capsules of what appears to be moss growing on this tree. The—dare I say—"moss flowers" are very tiny, sub-millimeter. I'll post a full-res crop in the reply because the structure of the rosette is 🤯.
f/2.4, 8.8mm (equivalent to 24mm on a film camera), so the depth of field is razor thin. The side of the lens is resting on the tree, leaving the middle of the lens maybe two centimeters away from the subject.
(Yes that's a Brian Jacques nod.)