Gregory M. Mueller, Ph.D., serves as the Negaunee Foundation Vice President of Science at the Chicago Botanic Garden. Before joining the Garden, Dr. Mueller worked for 23 years at the Field Museum as curator of mycology in the Department of Botany. He was chair of the Field Museum's Department of Botany from 1996 to 2005. Mueller received his B.A. and M.S. from Southern Illinois University, Carbondale, and his Ph.D. from the University of Tennessee.
I don’t have to look outside to know that it has been raining lately. My phone has been ringing off the hook with calls from the Illinois Poison Center requesting help with potential mushroom poisoning cases. I helped with four different cases today! Three of them involved children; the other was a case of an adult eating something that “looked good to eat.”
Chlorophyllum molybdites, the green-spored lepiota, was the mushroom du jour. Three of the cases involved this toxic mushroom that is commonly found in yards after summer rains. It looks lovely, and it usually won’t kill you, but I’m told that it makes one sick enough that people think that they might die. Symptoms involve vomiting and/or diarrhea, often severe, starting one to three hours after ingestion. This is the most commonly eaten toxic mushroom in the United States.
Today’s other culprit was Panaeolina foenisecii, known as the lawn mower’s mushroom, also commonly found growing in lawns. Unlike Chlorophyllum molybdites, this is no beauty. It is an LBM (little brown mushroom). It too can cause gastric upset and has been reported to cause slight hallucinations in some cases, but never in the numerous cases in which I’ve been involved.
Not all mushrooms growing in lawns are toxic. But the only way to tell is to know what the mushroom is (identify it). There are no short cuts or tricks to knowing whether a mushroom is toxic or not, so think before you eat! There are a number of mushroom books that can help (I’m partial to Wild Edible Mushrooms of Illinois and Surrounding States by my colleague Joe McFarland and me). And a great way to learn mushroom identification is to join a club like the Illinois Mycological Association.
Identifying mushrooms and plants for the Illinois Poison Center and hospitals is something that I and other Chicago Botanic Garden staff gladly do. Freely sharing our expertise is part of the Garden’s commitment to the region.
Foraging for edible mushrooms is a treasure hunt that always yields a reward. You never know what you’re going to find. At the least, you’ve spent enjoyable time outdoors in nature.
My tools are simple: a hand lens, knife, and a flat-bottomed basket that prevents any mushrooms I’ve collected from scrunching together. I like to wrap my finds in wax paper or wax paper bags. Paper bags can work too, but mushrooms tend to dry out after a while. (At the other extreme, mushrooms wrapped in plastic tend to sweat and can develop undesirable molds.) I typically head out in long pants and a long-sleeved shirt—protection against the poison ivy and bugs abounding in the woods.
I also carry knowledge that helps me discern among the more than 1,200 types of mushrooms identified so far in the Chicago metropolitan area. For more than 30 years, I’ve researched the vital role that fungi play in ecosystems around the world (but my interest in mushrooms and love of nature extends well beyond the laboratory).
Great finds: black trumpets, and more importantly—chanterelles!
Summertime is the fruiting season for two of my favorite edible mushrooms: chanterelles (Cantharellus cibarius) and black trumpets (Craterellus cornucopioides). Chanterelles are one of my very, very, very favorite things to collect.
I look for chanterelles in oak woodlands because chanterelles and oaks need each other to survive. The long fibrous root system of the chanterelle’s mycelium—the long-lived part of the mushroom comprised of microscopic filaments that grow through the soil—forms a protective sheath around the roots of the oak and provides the tree with water, nitrogen, phosphorus, and other nutrients. The symbiotic relationship allows the chanterelle to take up excess sugar the tree has produced through photosynthesis. We wouldn’t have a forest without mushrooms like chanterelles, and we wouldn’t have chanterelles without a forest.
Chanterelles have a yellow-gold color that makes them somewhat easy to spot on the woodland floor, and they offer up a fruity, apricot-like smell when picked. They do, however, bear a resemblance to the toxic jack-o-lantern mushroom (Omphalotus olearius), the second-most common mistakenly eaten mushroom in the United States. (The green-spored lepiota [Chlorphyllum molybdites] is the most common.) We can tell chanterelles from jack-o-lanterns when we turn them over and look at the underside of the cap: chanterelles are nearly smooth to strongly ridged, while the jack-o-lantern has well-developed gills like a grocery store mushroom.
Chanterelles are also getting a closer look from the scientific community. Until fairly recently, we assumed that the chanterelles growing around the world belonged to a single species. Subtle differences in color and size were attributed to normal variations within a species. DNA analysis suggests that the chanterelle genus contains myriad distinct species. My team of researchers has found three different types growing in the Chicago area alone, and we believe this is just the tip the iceberg. The findings have important implications for plant conservation. What are the threats to individual species of chanterelle? What will happen to local ecosystems if a unique species is lost?
In early August I discovered my first chanterelles of the season growing in a nearby oak woodland. I won’t harvest these—it’s illegal to collect mushrooms in forest preserves in counties surrounding Chicago—but I can imagine the delectable mushrooms sautéed in butter or a little olive oil, and minimally seasoned (so I can enjoy the pure chanterelle taste). For a more substantial dish, a chanterelle omelet is just to die for. You can learn more about the mushrooms growing throughout the region at the upcoming Illinois Mycological Association Show. Maybe I’ll see you there.
Recently, I helped kick off an exhibition of artwork focusing on wildflowers and other plants found in midwestern woodlands and prairies. This amazing show, at Ryerson Woods in Riverwoods, Illinois, features works by members of the Reed-Turner Artists’ Circle, some of whom teach in the Joseph Regenstein, Jr. School of the Chicago Botanic Garden. This exhibition and activities related to it provide a terrific example of what a “citizen artist” program can accomplish, helping to protect our native plants and the benefits they provide humankind by documenting their beauty and engaging the public.
The Artists’ Circle works to further the interests of botanical art, conservation science, botany, and horticulture at the local level. To highlight the beauty and importance of plants in our lives, the Artists’ Circle promotes and exhibits members’ work in collaboration with local and regional institutions.
In my opening remarks, I spoke briefly about how all life depends on plants, which is one of the basic tenets of the Chicago Botanic Garden. Plants provide us with food, shelter, oxygen, and medicine; they also provide vital services such as climate regulation, air and water quality improvement, and flood control. Yet we are in the midst of a well-documented plant biodiversity crisis, and some experts estimate that up to one-third of the world’s plant species may become extinct within the next 50 years. Unfortunately, far too little is being done to address this crisis. In fact, much of society suffers from “plant blindness”—aninability to see or notice the plants in one’s own environment.
Members of the Artists’ Circle, thankfully, are acutely tuned in to the environment, viewing plants and their role in the world with a unique clarity of vision. Not only are they producing beautiful works of art, they are thinking about developing a “citizen artist” program, and some members have been brainstorming about this idea with me. This program would parallel and enhance the important work that citizen scientists are performing throughout the region and beyond, through Garden involvement in such programs as Project BudBurst and Plants of Concern.
The Drawn to Nature IIexhibition, which runs through April 30, highlights the important contributions of botanical artists. It is impossible to be unimpressed by the beauty and complexity of plants when viewing the outstanding drawings and paintings here, created by members of the Artists’ Circle. The subtlety of the art prompts the viewer to see these objects of nature in a new light, eliciting a powerful, emotional response. By provoking such a visceral response, botanical art becomes an effective tool in fighting plant blindness.