This is one of the Rosellinia species with a well-developed and persistent subiculum. The subiculum is a mat-like growth of brown fungal hyphae on the surface of the wood and asexual spores are produced on the subicular hyphae. The subiculum develops first and later the more-or-less globose perithecia (each within a dark, blackish-brown shell) push out through the subiculum and sexual spores are produced in the perithecia. In some species of Rosellinia the subiculum is present only in young material and disappears (or at best becomes very scanty) as the perithecia mature.
@Heinol Do I need a permit to take a small specimen if I happen to see this particular fungus again? If it's ok to take a small specimen, what should it include and how stored? In a zip lock bag?