Wolf's-Milk Slime (Toothpaste Slime)

Media
Photo of wolf's-milk slime, a small pinkish rounded slime mold
Safety Concerns
Name
Not recommended/not edible
Scientific Name
Lycogala epidendrum
Family
Reticulariaceae (reticulate slime molds) in phylum Amoebozoa (amoeboid protists)
Description

Wolf's-milk slime looks like little, round, reddish pink balls; they exude a pinkish-orange or pinkish-gray paste when popped. It grows in groups on dead wood, especially large logs. June–November. The fruiting bodies are round; the outside is bright pinkish orange when young, becoming tannish olive with age; the inside is bright pinkish orange to pinkish gray, becoming ocher with age; the outside texture is smooth; the inside texture is pastelike, becoming powdery with age. The spore print is pinkish gray to ocher. The spores, magnified, are round and netted. This slime mold resembles a tiny reddish pink puffball. Before it is fully mature, you can pop it and a pinkish orange substance, with the texture of toothpaste, will ooze out.

Lookalikes: None in Missouri.

Size

Fruiting body width and height: ⅟₃–⅝ inch.

Where To Find
image of Wolf's-Milk Slime Toothpaste Slime distribution map

Statewide.

Grows in groups on dead wood, especially large logs. Thought it may seem like one, this species isn't actually a mushroom or fungus. It belongs to a group called slime molds, or myxomycetes—a group of funguslike organisms that at one time were regarded as animals, then thought to be plants, then fungi. Now, because of DNA studies, slime molds are believed to be closer to the protozoa. They are studied by botanists and mycologists.

Not edible.

Life Cycle

Slime molds are in a different kingdom from fungi and are more closely related to single-celled organisms. They have two life-cycle stages. The first, “plasmodium” stage is rarely noticed. It is like a huge, single-celled amoeba that creeps on dead plant material in long thin strands, engulfing and digesting bacteria, yeasts, and fungi. When ready to reproduce, it enters its funguslike “sporangia” stage, which makes spores that float away to become new plasmodia elsewhere.

Slime molds are weirdly beautiful and have even inspired science fiction movies (such as "The Blob" in 1958). They are studied for their unusual cellular characteristics. We include this species here because mushroom hunters and hikers see it a lot and many assume it's a fungus.

This species feeds on bacteria, yeasts, and fungi that colonize decaying materials such as rotting wood. It is in turn consumed by other organisms, such as fungi, nematodes, and perhaps small insects—all at a tiny scale, at the base of the ecosystem.

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About Mushrooms in Missouri

Mushrooms are a lot like plants, but they lack chlorophyll and have to take nutrients from other materials. Mushrooms are neither plants nor animals. They are in a different kingdom — the fungi. Fungi include the familiar mushroom-forming species, plus the yeasts, molds, smuts, and rusts.

Always be cautious when eating edible mushrooms. Be absolutely sure of the ID, and only eat a small amount the first time you try it to avoid a reaction..