Tim Lockley: These fungi raise a stink, but don't judge them

Tim Lockley

The stinkhorns are emerging a little early this year and, unlike previous years, the one I'm seeing aren't the "dead man's fingers" that I'd normally expect. As often as not, they're Ravenel's stinkhorn. Most of the time, the fungus is unseen and, more importantly, unsmelled; its fine strands of mycelia growing in the soil feeding on dead organic material. Mushrooms are the Earth's greatest decomposers. They are an important part of the environment, helping to break down dead material into simpler compounds that create a healthy, fertile soil. When a fungus matures, and when the weather is just right, it produces a fruiting structure...the mushroom.

Pagan peoples in Europe thought the appearance of stinkhorns predicted whether they would have a good crop that year. They were partially right, but for the wrong reason. They rationalized that, since Ravenel's stinkhorn resembled a male body part, it was a sign of fertility. The more stinkhorns they saw, the larger the harvest would be. Since fungi add fertilizer to the soil and the number of mushrooms could indicate how well the fungi was doing its job, a large number of mushrooms emerging could give you a rough idea as to the soil's fertility. The people of the Middle Ages, however, put a different interpretation to the emergence of stinkhorns. The believed that there was a demon in the ground lying in wait for an unsuspecting virgin to wander by.

Like its relatives, Ravenel's stinkhorn starts as a "witch's egg" (the Dark Ages again). The egg (easily removed with a nine iron) initially resembles a white puff ball but can grow into a 15-centimeter (6-inch) mushroom in less than a day. Once the mushroom is fully grown, the stench begins. This odor attracts all sorts of scavengers, such as bottle flies and fungus beetles. It can even bring in small rodents. To these guys, a stinkhorn probably smells like a T-bone steak on a barbecue grill. Occasionally, you'll see the mushroom literally covered in flies as thy wallow around the smelly slime. In the process of consuming the ooze, the scavengers pick up the spores produced by the mushroom and transport them hither and yon, spreading the fungus throughout the landscape.

Stinkhorns are more of a nuisance than a serious problem. They occur only once or twice a year and aren't poisonous. In fact, they're sold as food in markets in Europe and Asia.

If you want to try and do something about them, you can help reduce their spread by removing the mushrooms before they open. Wear gloves and carefully pick or dig them up while they're still in the egg stage. Place them in a plastic bag, zip it tight and throw it away. Next, look for the fungi's food source. If it's mulch, remove it by either incorporating it into the soil or, better yet, get rid of it completely. Stinkhorn fungi really like hardwood chips. If you want to use a mulch, try pine straw. Otherwise, consider replacing your mulch with a ground cover like Asiatic jasmine, liriope or mondo grass.

It may be that the fungi is working on a large dead root from a tree. If that's the case, you may have to live with stinkhorns. Just remember, stinkhorns are not a fungal disease. They're one of the good guys. Fungi have been around longer than we have. Trees and other plants need fungi in order to take up nutrients from the soil. If there had never been fungi, there would never have been forests. Add to that, climate change is making the planet warmer and wetter. So, it's very likely that fungi will continue to flourish long after we have disappeared. This is the fungi's world and we're, in geological time, just visiting.

Tim Lockley, a specialist in entomology, is retired from a 30-year career as a research scientist for the U.S. Department of Agriculture. For answers to individual questions, please send a stamped, self-addressed envelope to Tim Lockley, c/o Sun Herald, P.O. Box 4567, Biloxi MS 39535.