Ruzenia spermoides has tightly packed clusters of smooth, black, almost spherical perithecia, often in large groups on rotten wood. Both There are other similar species and detailed examination is needed.

There are many similar species

microscopy

Photograph the fungus on the substrate, and note habitat and substrate in your comments.  We recommend that this is verified by an expert from a specimen before submission to Naturespot. 

Rotten wood