Backyard Nature: Fascinating Fungi

by Marjorie Rachlin

As soon as we get a good soaking rain, there will be a lot of fall mushrooms on our lawns and in Rock Creek Park. But even without the rain, there are mushrooms about.

Take a walk and look around – they are an intriguing part of the ecology, in many colors and shapes, some on the ground and some on dead tree limbs.

Please don’t eat them. Many look enticing, but there are a few deadly species that I often see on Forest Hills lawns. The most dangerous, which usually appears in September, is a lovely white mushroom, about 4 to 6 inches tall, known as “ the destroying angel.” It is an amanita (genus). You will often see a patch of three or four, and they look to the untutored eye like the common mushroom we buy in the store.

This mushroom and several other species in the amanita genus contain a toxin that will kill you.

These amanita mushrooms look good enough to eat, but they are poisonous. (photo by the author)

A number of other mushrooms that look tasty will make you very sick. Only experts should eat wild mushrooms – join the Mycological Association of Washington (mawdc.org) if you are hungry and want to learn more.

Is that mushroom like a flower?

[col_1_3 style=”box border box_blue”]Rock Creek Park will host a mushroom hike for Junior Scientists (ages 6 to 12) and their families on Thursday, Sept. 5th, 4:00 p.m., at the Nature Center.[/col_1_3]I asked this and many other questions of Connie Durnan, a member of the Mycological Association. “No,” was the answer. When you see a mushroom, you are seeing the fruiting body which carries the reproductive spores, but it is not a flower. Mushrooms are fungi. They reproduce asexually – there are no male and female parts as in plants.

Their “roots,” called mycelia, are below ground or sunk in dead wood. These roots are decomposing organic matter and “feeding” on that. Mushrooms in your lawn or tree box, mean there is a lot of organic matter down there somewhere.

Some mushrooms are found only on dead wood. Here is a picture of a lovely shelf mushroom (polypore) called “chicken of the woods,” growing on a dead tree in Rock Creek Park.

Chicken of the woods in Rock Creek Park. (photo by Pat Davies)

A mushroom cap contains hundreds of spores, which function like seeds. Spores are tiny, different colors and shapes in the various species. They may be dispersed by the wind, or by an insect or animal that eats the mushroom. If a spore lands in a place where there is the right kind of organic matter, it may “germinate,” grow mycelia and eventually another mushroom. Experts often identify mushrooms by taking spore prints (put the mushroom cap, underneath side down, on a white piece of paper).

What makes fungi different

All of us learned about plants and animals in school. But mushrooms are fungi, a totally separate “domain” that also contains yeasts and molds. Plants carry on photosynthesis and make their own food (which animals eat) – but fungi cannot do photosynthesis.

Mushrooms get their “food” by decomposing organic matter (leaves, grass, bark, wood, dung, logs, dead tree roots, pinecones, etc.). The mycelia break it down into chemical compounds and elements such as nitrogen and potassium. In this way organic matter becomes food for themselves and also available to plants. This is an important ecological task – mushrooms are part of the vast army of decomposers that recycle dead stuff and enrich the soil.

What are we seeing now?

There are spring, summer and fall mushrooms, so new species appear as the weather changes. A foray by the local expert group two weeks ago found 40 species of mushrooms in Rock Creek Park. Often the same mushrooms will come up in a particular spot for many years, because the mycelia are underground working away all year.

Neighbor Pat Davies found these mushrooms in Rock Creek Park recently.

Shelf mushrooms on dead wood are known as polypores. (photo by Pat Davies)

Oyster mushrooms in Rock Creek Park. (photo by Pat Davies)

The photo below is a boletus, a common mushroom in the fall around here. The boletus mushrooms are often found under oak or conifer trees – they have a symbiotic relationship with the trees. The mushroom wraps its mycelia around oak roots and gives the oak nourishment as the mushroom breaks down organic matter; the tree roots give the mushroom the products of photosynthesis. This is called a mycorrhizal symbiosis – they both need one another.

Boletus mushroom. (photo by Pat Davies)

Fall is a good time for puffballs – I have seen lovely white ones, ten inches in diameter, in Rock Creek Park and in neighbors’ gardens.

Puffball mushroom. (photo by Wing-Chi Poon, courtesy Wikimedia Commons)

So, take a walk, and keep your eyes out! We’d love to know what you see. Marlene Berlin sent me this photo, but I have not been able to identify it. Does anyone have any ideas?

For more information:

The Mycological Association of Washington, Inc. (mawdc.org) welcomes newcomers at their monthly meetings and field forays. For a field guide, try the Audubon Guide to Mushrooms of North America, or even better, Mushrooms of West Virginia and the Central Appalachians by William Roody (paperback).

People are also putting mushrooms to work, not just putting them on our dinner plates. Read more in the July/August issue of Discover Magazine.