Plant · Fungi
Stinkhorns
Stinkhorns are among the strangest fungi a family can stumble across in an American backyard or forest, rising overnight into wild alien shapes and announcing themselves with a powerful rotting smell. They are harmless to touch and endlessly fascinating to examine up close.
This Outside Knowledge Network page covers stinkhorns, a group of wild fungi in the order Phallales known for their rapid growth, bizarre forms, and strong odor. The page includes identification guidance, regional information for American families, notable facts for kids, look-alike notes, and safety context. Stinkhorns are not dangerous to handle but should never be eaten without expert verification. Content is written for parents and children ages 4 to 14 by Outside, the family adventure app.
| Region | Most of continental United States |
|---|---|
| Safety | Safe to touch; never eat without expert ID |
| Season | Late spring through fall; year-round in the South |
| Habitat | Mulched beds, compost, deciduous forest edges |
| Difficulty | Easy to spot by sight and smell |
What you are looking at
Stinkhorns are fungi, not plants, though they push up from the soil like something planted there overnight. The most commonly encountered species in North America is the common stinkhorn (*Phallus impudicus*), which emerges from a white egg-shaped sac buried just beneath the soil surface. At full height it stands four to eight inches tall, with a spongy white stalk and a dark olive-green cap covered in a slippery, foul-smelling slime called gleba. That slime is the spore mass, and the smell is the whole point. Nearby you may also find latticed stinkhorns (*Clathrus ruber*), which form a bright red cage or basket shape, and the dog stinkhorn (*Mutinus caninus*), which is slender, orange-red, and smaller than its more famous cousin.
Where families run into them
Stinkhorns grow across most of the continental United States, from the humid Southeast to the Pacific Northwest and into the Midwest. They favor wood chips, mulched garden beds, compost piles, and the edges of deciduous forests where decaying organic matter is plentiful. Many families first encounter them not on a trail but in their own backyard, especially after a landscape crew has spread fresh hardwood mulch. They fruit most vigorously in warm, wet weather, typically late spring through fall. In the South they can appear nearly year-round. If you find one, look carefully at the base of the stalk for the white egg sac, which is how the fungus starts its life above ground.
How to know the smell is the point
Stinkhorns do not spread their spores by wind the way most mushrooms do. Instead, they produce a slime that smells powerfully of rotting meat or dung, which attracts flies and other insects from surprising distances. The insects land, walk across the cap, and carry spores away on their feet and bodies when they leave. It is a brilliantly efficient system, and it happens fast. A stinkhorn can push up from its egg sac and reach full height in just a matter of hours, one of the fastest growth rates recorded in the fungal world. By the time the spore slime is gone, usually within a day, the fly delivery service has already done its work.
The egg in the ground
Before a stinkhorn breaks the surface, it lives inside a white or pale lavender egg, roughly the size of a golf ball or slightly larger, connected underground to a cord of fungal tissue called a rhizomorph. You can find these eggs by gently probing the soil or mulch near an adult stinkhorn. Slice one open carefully and you will see the fully formed stinkhorn packed inside like a coiled spring, ready to expand. Some foragers in Europe have eaten the eggs of certain stinkhorn species, but the Outside rule applies here: never eat any wild fungus without having it identified and cleared by an expert mycologist. The eggs of unrelated toxic species can look similar.
Look-alikes and the calm family rule
Mature stinkhorns are nearly impossible to confuse with anything dangerous because their shape and smell are so distinctive. The egg stage is trickier. White egg sacs in the ground can resemble the eggs of Amanita mushrooms, a group that includes some of the most toxic species in North America, such as the death cap (*Amanita phalloides*). This is exactly why the standing family rule matters: look freely, smell if you like, but do not eat anything found wild without an expert's confirmation. Touching a stinkhorn is fine. They cause no rash or irritation. Wash your hands afterward as you would after handling any soil or organic material, and move on with the adventure.
What to bring home from the encounter
Stinkhorns reward the curious family with a genuine field science moment. Photograph the full fruiting body from a few angles, then look for the egg sac at the base. Count any flies or beetles visiting the cap. Note the time of day and check back in 24 hours to see how much has changed. Kids who sketch what they see in a field journal tend to remember the details far longer than those who only take a photo. Ask everyone to describe the smell in their own words without using the words bad or gross. The answers are always more creative than you expect.
Find a way to describe the smell of a stinkhorn without using the words bad, gross, or disgusting. Then draw the stinkhorn and label every part you can see, including anything visiting it while you watch.
Frequently asked questions
Are stinkhorns dangerous to kids or pets?
Stinkhorns are not toxic to touch and cause no skin irritation. Dogs sometimes eat them, and while stinkhorns are not considered poisonous, eating unknown wild fungi is never a good habit for pets or people. If a pet consumes a large quantity of any wild mushroom, contact your veterinarian.
Why does my mulch smell like something died?
A stinkhorn is almost certainly the culprit. The fungi grow eagerly in fresh hardwood mulch and produce a rotting-meat odor to attract flies. The smell fades within a day or two as the spore slime is carried away. Removing the fruiting bodies and their underground egg sacs can reduce future growth, but the fungal network in the mulch itself is hard to eliminate entirely.
How fast do stinkhorns grow?
Stinkhorns are among the fastest-growing fungi known. A fruiting body can emerge from its egg sac and expand to full height in just a few hours, driven by rapid water uptake and cell expansion rather than the slower cell division seen in most organisms. Setting up a time-lapse photo over an afternoon is a genuinely rewarding family experiment.
Can you eat stinkhorns?
Some stinkhorn eggs have been eaten in parts of Europe and Asia after cooking, but Outside's standing guidance applies: never eat any wild fungus without having it positively identified by a trained mycologist. The egg stage of stinkhorns can resemble eggs of Amanita species, which include some of the most dangerous mushrooms in North America.