ate, 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._

[Illustration: Figure 495.--Xylaria polymorpha. Natural size.]

Polymorpha means many forms. It is nearly fleshy, a number usually
growing together, or gregarious; thickened as if swollen, irregular;
dirty-white, then black; the receptacle bearing perithecia in every
part.

This plant is quite common in our woods, growing about old stumps or on
decayed sticks or pieces of wood. The spore-openings can be seen with an
ordinary hand-glass.

_Xylaria polymorpha, var. spathularia._

[Illustration: Figure 496.--Xylaria polymorpha var. spathularia. Natural
size.]

Spathularia means in the form of a spathula or spatula. It is vertical
and stipitate, the stem being more definite than in the X. polymorpha,
the stroma being between fleshy and corky, frequently growing in
numbers or gregarious, turgid, fairly regular, dirty-white, then
brownish-red, finally black. An ordinary hand glass will show how it
bears perithecia in all its parts. This will be clearly seen in the
section on the right.

These plants are not as common as the X. polymorpha, but are found in
habitats similar to those of the other plant, particularly around maple
stumps or upon decayed maple branches.

_Stemonitis. Gled._

Stemonitis is from a Greek word which means stamen, one of the essential
organs of a flower. This is a genus of myxomycetous fungi, giving name
to the family Stemonitaceae, which has a single sporangium or aethalium;
without the peculiar deposits of lime carbonate which characterize the
fructification of other orders, and the spores, capillitium, and
columella are usually uniformly black, or brownish.

_Stemonitis fusca. Roth._

[Illustration: Figure 497.--Stemonitis fusca. Natural size.]

Fusca means dark-brown,