Dog Vomit Slime Mold (Scrambled Egg Slime Mold)

Fuligo septica


Photo of dog vomit slime mold, closeup, extruding red liquid.
Drops of red liquid often form on the surface of dog vomit slime mold.
Lisa K. Suits
Not recommended/not edible

Physaraceae, in the class Myxomycetes (plasmodial slime molds, in the kingdom Amoebozoa or Protista)


Yellow, tan, or whitish fluffy or foamy-looking mass, becoming dried, crusty, and dark, eventually releasing many, many spores. Late spring through fall; common when it is hot and humid. Plasmodium (growth) stage a plate-sized, irregular mass that "creeps" gradually over wood mulch or other substrate; yellow, tan, or whitish; texture fluffy or foamy, slimy, soft, sometimes bleeding dark fluid. Sporangium (spore-producing) stage dries and hardens; becoming dark tan, brown, or black; eventually becoming a mass of dark, dusty spores. Spores pinkish-brown. Spores magnified are round, slightly spiny.

Lookalikes: There are many other species of slime molds, but this is one of the most common and noticed, as it looks amazingly like a foamy or spongy patch of dog vomit or scrambled eggs.


Width: to about 8 inches; height: to about 1¼ inches.


Photo of dog vomit slime mold, very young patch on landscaping mulch.
Dog Vomit Slime Mold
Dog vomit slime mold starts out soft and pale and eventually matures to a hard, dark crust.


Photo of crusty dark dried slime mold on landscaping mulch.
Dog Vomit Slime Mold (Scrambled Egg Slime Mold)


Photo of crusty dark slime mold on landscaping mulch.
Dog Vomit Slime Mold (Scrambled Egg Slime Mold)


Photo of dog vomit slime mold, bright yellow specimen.
Dog Vomit Slime Mold
The frothy bright yellow look of early stages of dog vomit slime mold makes it look like scrambled eggs. But it’s not edible.
Habitat and conservation

Not a true mushroom or fungus. Grows in irregular patches on mulch, decaying wood, or other rotting plant material, in warm, humid weather. It "creeps" gradually across the mulch surface, sometimes onto nearby living plants. Many people discover it on landscaping mulch and wonder what it is. When you run water onto its spore-producing stage, the water either rolls off it without moistening it, or else a cloud of spores rises up like smoke.

image of Dog Vomit Slime Mold Scrambled Egg Slime Mold distribution map
Distribution in Missouri



Not edible. There are reports that it is eaten in Mexico, however. This species is not known to cause sickness in humans, although the many dusty spores can irritate people with allergies, asthma, or other respiratory conditions. Although it can be unsightly in a flower garden, it is fairly impossible to get rid of this slime mold. Water only helps spread it, and completely changing mulch is only a temporary solution.

Life cycle

This isn’t a mushroom at all. It’s a slime mold, more closely related to single-celled organisms. It has two life stages. The first, “plasmodium” stage is like a huge amoeba that creeps like a blob over dead wood and other materials, engulfing and “eating” bacteria, yeasts, and fungi. When ready to reproduce — often when food runs out or conditions become too dry — it enters a dry, dusty “sporangia” stage, making spores that blow away to start new plasmodia elsewhere.

Human connections

Although it can be a nuisance to gardeners, this slime mold has proven useful for scientists studying how genes work within cells. This slime mold also produces chemicals that may be useful in treating cancer.

Ecosystem connections

This is one of many strange, humble organisms that feast on decaying organic materials and the microbes that inhabit them. They have an incredibly important role in breaking down the tough materials living things are made of and returning those nutrients to the soil.