What is that in my soggy lawn, and can I eat it?

When it stops raining for a moment, I slosh into my backyard, just to look around and make sure none of my neighbors is building an ark.

In the soggy turf at my feet -- where nothing had been the night before -- sprouts a passel of puffballs, a flock of fungi, a mob of mushrooms.

"There's all kinds of fungi growing our there now," says Anton "Bud" Weber, a veteran master gardener from Wheeling, who mans the plant information hotline for the Chicago Botanic Garden in Glencoe. "I have at least four kinds of mushrooms growing in my yard."

While the recent rain and floods have caused heartache for some suburbanites, these truly are the salad days for local mushrooms.

"It's a good year," says Patrick R. Leacock, adjunct curator in the botany department at Chicago's Field Museum and a frequent lecturer at The Morton Arboretum (www.mortonarb.org) in Lisle. As part of a joint project with the museum, arboretum and botanic gardens to compile a searchable database of 72,000 local plants at www.vplants.org, Leacock lists nearly 1,000 fungi specimens that can be found in the city and suburbs.

Many of the mushrooms at www.vplants.org/resources/links3.html are edible. So folks who don't know shiitake from chanterelle might be tempted to fry up whatever they find in their yards.

"But you don't want to do that," Leacock warns.

"No, no, no, no. That's one of the worst things you can do," Weber concurs.

Some mushrooms (especially those that grow on trees) can kill people.

"Most of those are in the forest, instead of in people's yards, but there is one large, good-looking mushroom that is poisonous for some people," Leacock says. Eating chlorophyllum (which means "green gills") often leads to diarrhea, vomiting and even kidney problems.

Even if you are sure the mushroom in your yard is one you can eat, "forgo the temptation," says Catherine Lambrecht, former president of the Illinois Mycological Association (e-mail sukayser@gmail.com for club information). The Illinois Mycological Association hosts a fungi exhibit from 10 a.m. until 4:30 p.m. Sept. 2 at the Chicago Botanical Gardens (www.chicagobotanic.org).

The moral of any suburban lawn mushroom story is "don't eat it" even if you think it's a much-storied morel.

"Even if a mushroom is an edible, you don't know how the neighbors treated their lawn," Lambrecht warns. "It's not that the mushroom itself is bad, it just picks up stuff in its environment."

Mushrooms soak up the pesticides, herbicides, heavy metals and other toxins, Leacock notes. That's part of the charm of fungi, which fall in the netherworld between plant and animals.

"They are providing a service," Leacock explains. "They are recycling dead roots and dead grass. They are in your ground feeding on dead, organic material. They are all ready to sprout. They are just waiting for rain. The small ones do pop up overnight."

And they can grow to be big ones. The 1992 discovery of a humongous fungus that covered 30 acres of forest on the Wisconsin-Michigan border has led to further claims of fungi that cover thousands of acres. Such media hype brings attention to fungi, which are just starting to get the attention they deserve, Leacock says.

"Ecologists are realizing the fungi are doing a lot of stuff underground," Leacock says.

That underground mushroom movement shouldn't alarm us. As long as you don't have young kids or pets that will eat them, most of the mushrooms will do their natural recycling and then disappear from sight when it gets dry. Even if you wanted to get mushrooms out of your yard, it's not that easy.

"You can't get rid of them," Leacock says, "unless you pour concrete on your yard."