Green-Spored Lepiota

Family: 
Agaricaceae
Description: 

Large, white, with broad, cream-colored scales on cap, white gills that turn gray-green, and a stalk ring. July–September. Cap round, becoming flat; white, with large whitish, pinkish, or cream-colored patches in center; patches breaking into many small scales when open. Gills broad; spacing close; white, becoming gray-green or darker; attachment free. Stalk enlarges toward the base; white, darkens when handled; texture smooth; upper stalk has ring. Partial veil leaving a ring on the stalk resembling a napkin ring. Spore print green. Spores magnified are elliptical, smooth, with small pore at tip.

Lookalikes: Most true Lepiotas have white spore prints. Reddening lepiota (Leucoagaricus americanas) bruises red. Parasol (Macrolepiota procera) has a tall, slender, scaly stalk. Agaricus species have brown spore prints. Thiers amanita (A. thiersii) has a white spore print. Shaggy mane (Coprinus comatus) has a cylindrical cap, turning inky with age, and black spores.

Size: 
Cap width: 2–12 inches; stalk length: 3–10 inches; stalk width: ¼ –1 inch.
Habitat and conservation: 
This mushroom is found in summer and fall, on the ground in lawns, pastures and meadows. They often appear in “fairy rings”—emerging as a circle of mushrooms—on suburban lawns. The fairy ring shape results from the growth pattern of the parent fungus, which lives in the soil. The circle of mushrooms marks the boundary of the fungus underground. Although these mushrooms can be quite large and abundant, resist the urge to eat them. Prevent your children and pets from eating them, too.
Distribution in Missouri: 
Statewide.
Status: 
Poisonous. This very common mushroom is not deadly, but it can make you sick, causing anything from a mild stomachache to serious illness and violent vomiting. Sometimes called the "green gill," as it is not truly in the genus Lepiota (which includes the closely related parasol mushrooms).
Life cycle: 
“Mushrooms” exist 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 sends up the “mushroom” or “toadstool” above ground; 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: 
These large, common mushrooms often appear in people’s lawns and are frequently eaten by the lawn’s owner—to his or her regret. They can cause violent gastrointestinal upset, including vomiting and diarrhea severe enough to require hospitalization.
Ecosystem connections: 
Fungi are vitally important for a healthy ecosystem. Many form symbiotic relationships with roots of many trees, helping them to survive. Fungi also feed off of decomposing materials, such as fallen leaves and logs, cleaning the forest and helping nutrients to cycle back into the soil.