Rhizina undulata, also know as Pine firefungus, is a large, irregular, brown or black fungus that grows in fused clusters on conifer debris, particularly in old fire sites.

Fruiting bodyflat, with irregular lobes, and attached to the growing surface on the entire lower side by numerous whitish to yellowish rhizoids resembling plants roots. The margin is pale yellow (like the underside), and wavy and irregular. Surface sticky as moist. Flesh is reddish brown, tough and thick.

Occurrence It is grows infrequently from early summer to early autumn.

Rhizina undulata on Wikipedia.