Some of the most curious fungi appear in fall.

With names like stink horns, puffballs, bird’s nests, and even Jack-o’-lanterns, all are interesting.

A warm and wet autumn is the ideal time for fungus to appear.

This natural occurrence may seem unsettling.

Many people notice mushrooms popping up in lawns and landscapes.

When mushrooms, also known as toadstools, appear in a circle or arc, it is commonly called a fairy ring.

According to folklore, this is where fairies danced in a circle.

Often there is a slight discoloration of the turf grass near the fairy rings.

Over the years, the rings of toadstools widen and may overlap.

Puffballs start small, perhaps the size of a marble and can become as large as a softball or basketball, depending on the species.

The giant puffball can reach the size of a bushel basket.

Unlike mushrooms, puffballs may have a short, wide stalk.

If you step on them, you might see the plume of brown spore-filled “smoke” puff into the air, helping establish the next generation of puffballs.

Bird’s nest fungi resemble miniature birds’ nests with tiny eggs.

A large nest might be one-half inch in diameter.

These are common in wood mulch.

No stalks grow on these fungi.

The spores are released from the mature “eggs.”

Stink horns emerge from witch’s eggs, the immature, underground egg stage of the stink horn, especially in mulched landscape beds.

The half-buried, elongated ping-pong balls open to release orange-red finger-like stalks that are four to six inches tall.

The stalks are topped with narrow caps of brownish-green slime.

The caps smell awful.

This putrid smell attracts flies that land and then carry off spores to germinate in other locations.

Stink horns are very short-lived.

Within a day or two, they collapse and vanish entirely in a week.

The Jack-o’-lanterns are among the most exciting mushrooms.

These pumpkin-colored beauties grow at the base of stumps or living oak trees.

Each cluster may contain 15 to 20 mushrooms with caps up to four inches in diameter.

These fungi are all saprophytes.

They break down organic matter to absorb nutrients from it.

They do not cause disease in live plants, so there is no danger to your lawn or landscape plants.

No treatment or fungicide will manage saprophytes in your lawn or garden.

Herbicides (weed killers) don’t work on fungi.

Fungicides do not manage these saprophytes.

Fungicides prevent disease-causing fungal spores from establishing on a green plant’s living tissue.

Fungi are natural recyclers of decaying wood and organic matter in the soil.

They are part of the clean-up crew in our environment.

The main portion of a saprophytic fungus remains underground.

The mycelium is made of delicate, white, hair-like structures that spread extensively throughout the organic matter or soil.

The part that we see is called the fruiting body.

It appears above the surface to distribute spores.

If you are concerned about their presence, the best strategy is to remove the fruiting body with a gloved hand or a trowel and drop it into the trash as soon as it appears.

Teach children that mushrooms are interesting and fun to look at, but they should never be touched or eaten unless they come from the grocery store.

“Growing Green” is contributed by Lehigh County Extension Office Staff and Master Gardeners. Information: Lehigh County Extension Office, 610-391-9840; Northampton County Extension Office, 610-813-6613