Don't Think of It as Dog Vomit. Think of It as Slime Mold.
By Adrian Higgins
Washington Post Staff Writer
Thursday, June 15, 2000; Page H09
If you are reading this while feasting on a breakfast omelet, you may wish to put this story aside until a little later. Make that a lot later.
As spring turns to summer, mulched garden beds become marked by large, slimy blobs that look like--how to put this gracefully?--dog vomit. The blobs can be several inches across, and they are variously bright yellow and slimy or tan and encrusted. In other words, repulsive.
There is no hiding them. Gardeners tend to be both embarrassed and fearful that this thing will damage valued plants. Even people who live in apartments cannot escape the blobs, which are bound to appear in the well-mulched beds at the building entrance.
"This is the season for it," said Susan DeBolt, extension agent in Prince William County. "We have been getting calls."
The culprit is a slime mold variously called wet cookie or dog vomit mold. You may prefer the scientific name, Fuligo septica.
Slime molds inhabit a murky area of life. Once studied as fungus, they are now considered closer to protozoans, or amoebas, though for part of their life cycle they morph into fungallike cells.
They don't smell; they do not harm plants, pets or children, but it takes a mycologist to appreciate them.
This is how they work: Individual, amoebalike cells hatch from spores and munch away on bacteria that is found in decaying wood--for example, the shredded hardwood mulch you laid in March.
Triggered by a number of factors, including warmth, late spring rains and depletion of food, the amoebas gather for a microbiotic orgy. The conjoined adults, called zygotes, keep multiplying into a single, oozing creature.
This is the eruption in the mulch, called a plasmodium by scientists. It is not only slimy but--this is the sci-fi bit--it moves as much as a yard in just a few hours looking for light and a place to disperse its millions of spores to the wind. "The plasmodium has a slime layer to prevent water loss, but the slime mass transforms into a fruiting body," said Steve Stephenson, a professor at Fairmont State College in Fairmount, W.Va.
The fruiting stage is marked by the crust--tan or light orange--with black spores beneath. "If you notice in the morning something had crawled out, it doesn't take more than a few hours for the transformation to occur," said Stephenson, author of "Myxomycetes: A Handbook of Slime Molds" (Timber Press, $19.95). Once, he said, he saw a slime mold erupt from the ground, decide not to fruit and crawl back into the soil. Creepy.
When the slime mold erupted widely in Texas in the 1970s, "some people thought it was an alien creature," he said. "It wasn't in the least alien."
Even though it might appear to be sentient, "there's no consciousness or anything like that: A grasshopper would be a total Einstein compared to a slime mold. There's no nervous system, there's no nothing."
Except revulsion, of course.
Other slime molds can be beautiful, said Amy Rossman, director of the U.S. National Fungus Collections in Beltsville. Unfortunately, these other species are less conspicuous than Fuligo. "Many are brightly colored," she said. "There's one in the woods you see a lot that has pink cushionlike things on the top."
Fuligo septica can be simply hosed away, though the act of hosing will cause the spores to be released.
DeBolt tells anxious callers to scoop up the plasmodium, being careful not to break it, and bag it and trash it.
Stephenson knows of another way of disposing of it. "Sometimes, not in Eastern North America, but in Mexico, some people on some occasions . . . (pause). It's actually eaten," he said.
"They collect it when it's still emerging as a slimy gook, they cook it and eat it. It tastes somewhat like almonds.
© 2000 The Washington Post Company
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