Common Stump Brittlestem vs Fly Agaric

Psathyrella piluliformis compared with Amanita muscaria

Taxonomic Classification

Rank	Common Stump Brittlestem	Fly Agaric
Kingdom same	Fungi (Fungi)	Fungi (Fungi)
Phylum same	Basidiomycota (Club Fungi)	Basidiomycota (Club Fungi)
Class same	Agaricomycetes (Mushrooms)	Agaricomycetes (Mushrooms)
Order same	Agaricales (Gilled Mushrooms)	Agaricales (Gilled Mushrooms)
Family	Psathyrellaceae	Agaricaceae (Agarics)
Genus	Psathyrella	Amanita (Amanitas)
Species	Psathyrella piluliformis	Amanita muscaria

Evolutionary Relationship

Common Stump Brittlestem and Fly Agaric share a common ancestor at the Order level: Agaricales. (Gilled Mushrooms)

Conservation Status

Common Stump Brittlestem

LC — Least Concern

Fly Agaric

LC — Least Concern

Trend: Stable →

Physical Characteristics

Attribute	Common Stump Brittlestem	Fly Agaric
Diet	—	Decomposer
Average Lifespan	—	1 years
Average Length	—	20 cm
Average Weight	—	100 g

Habitat & Geographic Range

Common Stump Brittlestem

Habitat

Typically found in forest floors, decomposing wood, and soil ecosystems.

Range

Widely distributed across Asia (Taiwan), Europe (5 countries), North America (United States), and South America (Brazil).

Fly Agaric

Habitat

Typically found in forest floors, decomposing wood, and soil ecosystems.

Range

Widely distributed across Europe (4 countries), North America (United States), Oceania and the Pacific (New Zealand), and South America (Brazil, Chile, Colombia).

Common Stump Brittlestem

<em>Psathyrella piluliformis</em>, the common stump brittlestem, is a saprotrophic basidiomycete fungus in the family Psathyrellaceae, order Agaricales. It has a broad distribution across Asia, Europe, and the Americas, typically found growing in dense clusters on or near the stumps and buried roots of deciduous trees, particularly oaks and beeches, from autumn through to early winter. The fruitbodies are hygrophanous, changing colour dramatically depending on moisture content, ranging from pale buff when dry to a rich honey-brown when wet. <em>Psathyrella piluliformis</em> plays an important ecological role as a wood decomposer, facilitating the breakdown of lignin and cellulose and contributing to nutrient cycling in forest ecosystems. The fragile, brittle gills and thin-walled spores are characteristic of the genus. Biological traits including average mycelial lifespan, fruiting body dimensions under natural conditions, and specific substrate preferences remain poorly documented. The species is assessed as Least Concern by the IUCN, reflecting its wide distribution and apparent abundance across temperate woodland habitats in the Northern Hemisphere and beyond.

Fly Agaric

Among the most iconic and recognizable fungi on Earth, fly agaric mushrooms display striking red caps with white flecked warts across boreal forests of the Northern Hemisphere. Despite their fairy-tale appearance, they contain potent psychoactive compounds including muscimol and ibotenic acid and are moderately toxic. They form critical mycorrhizal symbioses with birch, pine, and spruce trees, exchanging mineral nutrients for carbon and playing essential roles in boreal forest nutrient cycling.

Shared Countries

Both species can be found in 6 countries:

🇧🇷 Brazil 🇩🇰 Denmark 🇳🇴 Norway 🇵🇹 Portugal 🇸🇪 Sweden 🇺🇸 United States