Little Brown Mushrooms

Various species of confusingly similar mushrooms
Not recommended/not edible

Various species of capped mushrooms in the phylum Basidiomycota (fungi having basidia)


Into this catchall category go the hundreds of small to medium-sized mushrooms that are brown or tan and have the well-defined stalk and cap of a typical mushroom. Spore color, which is used to identify mushrooms, varies in this group. Even experts can have a great deal of trouble sorting “little brown mushrooms” into species. Because many are poisonous, and some deadly, we recommend avoiding the whole bunch.


Varies with species.

Habitat and conservation

Little brown mushrooms are found in spring, summer and fall, in all habitats. They may grow on soil or wood and may appear in lawns, pastures or forests. Because they are so difficult to identify, they should be avoided. Many "LBMs" are harmless, but some are mildly poisonous or hallucinogenic, and a few are deadly. The innocent-looking little mushrooms of the genus Galerina are probably the most dangerous of this group. They contain the same toxin as amanitas and have caused a number of deaths.

image of Little Brown Mushrooms Distribution Map
Distribution in Missouri




Life cycle

A fungus that creates mushrooms exists most of the time underground or within rotting logs as a network of cells (mycelium) connected to tree roots, rotting material and the soil. When ready to reproduce, the mycelium develops the mushroom aboveground; these 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.

Human connections

Even though the many species of “little brown mushrooms” cannot be safely eaten, we can still admire the geometry and delicacy of their growth forms, and appreciate the work fungi do to reduce tons of dead leaves, branches and other spent plant material into mulch and rich soil.

Ecosystem connections

Fungi are vitally important for a healthy ecosystem. Many form symbiotic relationships with roots of trees, helping or even enabling them to survive. Fungi also feed on decomposing materials, cleaning the forest and helping nutrients to cycle back into the soil.