Big Laughing Gym (Big Laughing Jim)

orange mushroom growing off a tree stump.
Safety Concerns
Scientific Name
Gymnopilus junonius (formerly G. spectabilis)

Large, orangish yellow, with a ring on the stalk. Grows in clusters on stumps and trunks, on ground, or over buried wood. August–October. Cap convex; orangish yellow to fawn; texture smooth with minute scales. Gills broad; light yellow to rust; spacing crowded; gills attached. Stalk with equal sides or club-shaped; light yellow to ocher; covered with tiny fibers; has a ring. Partial veil thin and fibrous, pale yellow, leaving a line or zone on the stalk. Spore print orange to rust. Spores magnified are oval to elliptical, wrinkled. Odor like anise; taste (chew on a tiny piece of cap, then spit it out) bitter.

Lookalikes: Honey mushroom (Armillaria mellea) is honey-colored with a white spore print. Ringless honey mushroom (Desarmillaria caespitosa) is honey-colored with a white spore print, but has no ring. Jack-o’-lantern (Omphalotus illudens) lacks a veil and has a whitish-cream spore print. Deadly galerina (Galerina autumnalis) is smaller and browner.


Cap width: 3–7 inches; stalk length: 2–8 inches; stalk width: ¼–1½ inches.

Where To Find
imge of Big Laughing Gym Big Laughing Jim Distribution Map


Grows in clusters on stumps and trunks of deciduous trees, on the ground, or over buried wood. The genus name "Gymnopilus" means "naked cap," apparently referring to the smooth-looking cap of the mushroom.

Poisonous. While there are stories of this mushroom having mild hallucinogenic properties (thus the name), those natural hallucinogens appear to occur only in very low amounts. Ingesting it is much more likely to make you sick, as this mushroom has been known to cause serious illness. Also, it is too bitter to eat.

Life Cycle

This species exists most of the time as a network of fungal cells (mycelium) within rotting logs, branches or tree roots. When ready to reproduce, the mycelium develops the conspicuous cluster of mushrooms, which are reproductive structures. Spores are produced in the gills and are released to begin new mycelia elsewhere. The mycelium of a mushroom can live for decades.

Several species of mushrooms and plants are used, in many cultures, for their ability—to varying extents—to cause hallucinations. Most of these fungi and plants also commonly cause sickness or even death. This species is more likely to make you sick than "happy."

This is one of the many fungus species that live on decaying wood. It and other such saprobic fungi play an incredibly important role in breaking down the tough materials wood is made of and returning those nutrients to the soil.

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Similar Species
About Mushrooms in Missouri

Mushrooms are a lot like plants, but they lack chlorophyll and have to take nutrients from other materials. Mushrooms are neither plants nor animals. They are in a different kingdom — the fungi. Fungi include the familiar mushroom-forming species, plus the yeasts, molds, smuts, and rusts.

Always be cautious when eating edible mushrooms. Be absolutely sure of the ID, and only eat a small amount the first time you try it to avoid a reaction..