Identifying mushrooms can be challenging when compared to identifying trees, birds, or butterflies. Challenges of identification stem from the lack of information collected in the field or lack of distinguishing features on the mushrooms collected. Fungi guides often rely on details that may be easily overlooked in the field or require microscope observations. But don’t let these challenges stop you from trying to identify that mushroom.
Before You “Pick” Your Mushroom
- Where is the mushroom coming from? This seems easy at first thought until you open the guide. Common questions in guides are: what type of tree was the mushroom found growing on, was the tree living or dead, or is the mushroom growing on the grass, wood chips, soil, or roots of a tree that was removed?
- What time of year was the mushroom collected?
- Is there one mushroom, or are there multiple mushrooms in the area? If multiple mushrooms, do they come together at the base, or are they distinctly separate?
- Is there a distinct smell around the mushrooms? Some mushrooms have distinctive smells to attract insects to help disperse their spores.
- It is beneficial to take photos of the mushroom before disturbing it. In the photo, be sure to include a size reference (a coin or a small ruler will do). A tripod may be beneficial to stabilize your camera. You will want photos of the entire mushroom (side profile), a close-up of the top of the mushroom, and the underneath side of the mushroom.
Be forewarned some mushrooms will turn colors once they are touched and may liquefy before you can get them home. (Don’t worry these are key characteristics of some fungi.)
“Picking” Your Mushroom
- Some groups of mushrooms are identified by looking at the base of the mushroom and some of these mushrooms even have tap roots. Digging around the mushroom with a spoon or a trowel will allow you to keep the base intact and see if a tap “root” is present.
- Once you have dug up your mushroom, you should place the mushroom in wax paper or a small paper bag to carry home. Avoid using plastic bags. If you are collecting mushrooms, you may want to number each package to match your observation notes.
- Try to keep the mushrooms out of direct sunlight and reasonably cool.
Making a Spore Print
Some mushrooms reproduce via spores which can be used to help with the identification. Individual spores can’t be seen with the naked eye. However, if the mushroom can produce spores, the spores will be produced in mass quantities. The spore production may also depend on how fresh the mushroom is and if it is immature enough to produce spores.
Spore prints are easy to do. First, you will want to remove the stipe (or stem.) If you have a large mushroom, you may need to take a section of the mushroom. Secondly, place the top of the mushroom called a cap on a piece of black paper and a piece of white paper side by side. Third, you will want to place a jar (or a plastic cup) over the mushroom to prevent the air currents from carrying away the spores. Let the mushroom sit on the paper overnight.
The following day, take a look at your spore print and record what color the spores are.
Here are some more words of advice. Do not compare your mushroom to photos in the field guide or on the web, more often than not this leads to misidentification. Use the key in the field guide. You may need multiple guides or web resources. Don’t be afraid to say I don’t know and move on to the next mushroom. It happens to the best of us.
Is it Edible?
Iowa State University does not make recommendations about the edibility of wild fungi. When consuming wild fungi, multiple factors may contribute to a potential poisoning, most of which are beyond the control of the person who identifies a specimen. Some edible and deadly poisonous mushroom species are not only similar in appearance but may be found growing together. The toxin content in individual mushrooms may vary, and the effect produced by toxins may vary from person to person. There are toxins in most “edible” species that must be cooked off in order to be safe, and some “edible” species are very toxic when consumed with alcohol (even within a few days). Fungi that are generally considered edible may cause serious allergic reactions when consumed by some individuals. Additionally, wild fungi often are contaminated with pesticides, pollutants, bacteria, or other decay organisms.
- Safe Mushroom Foraging from Iowa State University
- Iowa Mushroom Calendar
- Safe Mushroom Forging Guide (pdf)
- Tips for Hunting Wild Edible Mushroom (video)
- Mushroom Questions Answered for Home Gardeners
- Wild Mushrooms Certification
- Mushrooms and Other Fungi of the Midcontinental United States by Donald Huffman, Lois Tiffany, George Knaphaus, and Rosanne Healy. 2nd edition. Copyright 2008.
- Prairie States Mushroom Club
- Rogers Mushroom