Group of Fungi: Agarics

Family: Marasmiaceae

Latin Name: Megacollybia platyphylla (Pers.) Kotl. & Pouzar

Synonym(s): Tricholomopsis platyphylla (Pers.) Singer

Common Name: Platterful Mushroom

Description: Total height 3–5 in (7.5–12.5 cm); cap 2–4 in (2.5–10 cm) wide, bell-shaped when young but becoming broadly convex to flatten in age, brownish-gray, upper surface of cap with dark fibers that radiate outward from the center; gills somewhat widely spaced, white to pale gray; stalk 2 1/2–4 1/2 in (6.5–11.5 cm) long, 3/8–3/4 in (1–2 cm) in diameter, often slightly expanded at the base, white to grayish white, often with white cords (rhizomorphs) arising from the base; spores white in mass.

Biological Role: Decomposer of wood.

Habitat: On decaying wood (often buried in the soil) in broadleaf or conifer forests; usually solitary but sometimes occurring in small groups.

Geographical Distribution: Found throughout eastern North America and more rarely in western North America.

Comments: Megacollybia platyphylla is one of the first large agarics to appear in the spring and is often common throughout the summer. Although sometimes reported as edible, this fungus shouldn't be collected for human consumption because it sometimes causes an adverse reaction.