If you’ve walked past a tree stump or a pile of mulch around town this summer and seen something that looks like scrambled eggs — or, less appetizingly, like something the dog brought up — you haven’t found a fungus, and your tree isn’t sick. You’ve found a slime mold, and it’s one of the stranger things living in Rocheport right now.
The most common one you’ll run into this time of year is Fuligo septica, better known by its unglamorous common name: dog vomit slime mold, sometimes softened to “scrambled egg slime mold.” According to the Missouri Department of Conservation’s field guide, it shows up as a yellow, tan, or whitish foamy mass, usually spreading across mulch, decaying wood, or other rotting plant material during warm, humid weather — which is to say, exactly the stretch we’ve been having. It can grow up to about 8 inches wide and creep onto nearby living plants, which is usually the moment someone panics and calls it in.
Here’s the reassuring part: it isn’t a disease, and it isn’t hurting your tree. Despite the “mold” in the name, MDC’s guide notes it isn’t a true fungus at all — genetically, slime molds are closer to single-celled protozoa than to mushrooms, plants, or anything else most people would call alive. Earlier scientists tried classifying them as animals, then plants, then fungi, before DNA testing settled the question: they’re their own thing entirely. For a stretch of its life, a slime mold like this one exists as a single sprawling cell — no roots, no leaves, no bark to infect — that creeps across a surface consuming bacteria and fungi on dead organic matter. It’s a decomposer, not a parasite.
Watch one for a few days and you’ll see the whole show. The bright, foamy yellow stage doesn’t last — within a day or two it dries out, hardens, and darkens to tan, brown, or black, and eventually breaks down into a dusty mass that releases spores to start the cycle over somewhere else. If you catch one early and check back later in the week, that color change is the most interesting part of the whole encounter.
If you’d rather not have it on the mulch bed by the porch, MDC’s advice is simple: leave it alone, or rake it out and dispose of it before it dries — hosing it down just spreads the spores further. It’ll run its course either way. And if what you found looks less like scrambled eggs and more like small, round, reddish-pink balls clustered on a dead log — the kind that ooze an orange, toothpaste-like paste if you poke one — you’re probably looking at a cousin instead: wolf’s-milk slime, another harmless decomposer with the same basic story.
None of it means your tree is in trouble. It means the wood underneath is doing exactly what wood in a river-bottom town in August is supposed to do.
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