Lycogala epidendrum

Scientific name:  Lycogala epidendrum (L.) Fr.
Derivation of name:  epidendrum means "on wood" in
reference to its typical habitat.
Synonyms:  Lycoperdon epidendrum L.
Common name(s):  Wolf's milk slime; Toothpaste slime.
Phylum:   Myxomycota
Order:   Liceales
Family:  Reticulariaceae
Occurrence on wood substrate:  Saprobic; scattered to
clustered on well-rotted wood; June through November.  
Dimensions:  This slime mold forms fruit bodies 3-15 mm
wide.  
Description: The globose to subglobose or compressed
fruitbodies of Lycogala epidendrum are at first pinkish-gray
to bright cinnabar-red when young. At this stage the flesh is
a pinkish, paste-like substance (like toothpaste?). With
maturity the fruit body becomes yellow-brown or olive-
brown and the spore mass becomes powdery and pinkish-
gray to ochre in mass.
Edibility: Inedible.
Comments: Although many slime mold species fruit on
wood, slime molds do not form a penetrating and absorptive
mass of hyphae in the wood substrate. Rather, slime molds
form structures called plasmodia which are naked
(i.e., without cell walls) masses of protoplasm which can
move and engulf particles of food in an amoeboid manner.
Slime mold plasmodia creep about over the surfaces of
materials, engulfing bacteria, spores of fungi and plants,
protozoa, and particles of nonliving organic matter. At some
point, plasmodia convert into spore-bearing structures. In
Lycogala, the plasmodium converts into a globose to
hemispherical mass of spores enclosed by an outer wall
called a peridium. This structure is called an aethalium
(plural: aethalia).

More information at MidwestNaturalist.com

Figure 1. This log supports a typical fruiting of Lycogala
epidendrum. The globose to hemispherical masses of
various sizes are aethalia which developed from a
plasmodium or plasmodia. Photo © Gary Emberger.


Figure 2. Pinkish-gray younger specimens. The finely
textured surface is typical of Lycogala epidendrum.
Photo © William Roody.


Figure 3. A pinkish fluid oozes from a broken peridium.
This fluid becomes progressively more pastelike as it
matures into a dry mass of spores.
Photo © Gary Emberger.

Figure 4. Specimens with particularly intense pinkish-red
coloration. Lycogala epidendrum is not commonly
observed looking like this, leading to some uncertainty
about the identity of these specimens. However, the
plasmodium of Lycogala epidendrum is reported to be
reddish or coral red in color.These aethalia are probably
newly formed from the reddish plasmodia.
Photo © Gary Emberger.


Figure 5. The wet, sticky nature of the flesh inside is
revealed as it clings to the tip of the small stick used to
break open the peridium. Photo © Gary Emberger.

Figure 6. Maturing specimens of Lycogala epidendrum.
Photo © Fred Habegger.

Figure 7. Maturing specimen with a violet colored
spore mass. Photo © Gary Emberger.

Figure 8. At maturity, the coloration of the outside and
inside is quite different. In addition, the spore mass is dry
and powdery. Photo © Gary Emberger.

Figure 9. Steve Nelsen provided this photograph of
Lycogala flavofuscum which resembles L. epidendrum
but which is larger (2 cm or more in diameter), has a
thicker, nearly smooth peridium, occurs on living as
well as dead wood, and is not nearly as common.
Photo © Steve Nelsen.