This is quite common on partially decayed logs. The peridium is very thin, tuberculose, effused, delicate, olivaceous-brown; spores olive, echinulate or spiny.
Didymius xanthopus. Fr.
These are very small yellow-stemmed plants, found on oak leaves in wet weather. The sporangium has an inner membranaceous peridium; the whole is round, brown, whitish. The stem is elongated, even, yellow. The columella is stipitate into the sporangia.
D. cinereum. Fr.
Sporangia sessile, round, whitish, covered with an ashy-gray scurf. Spores black. Very small. On fallen oak leaves. Easily overlooked.
Xylaria. Schrank.
Xylaria means pertaining to wood. It is usually vertical, more or less stipitate. The stroma is between fleshy and corky, covered with a black or rufous bark.
Xylaria polymorpha. Grev.
