Giant Puffball

Calvatia gigantea

Edible when pure white inside

Also called giant puffball mushroom.

The giant puffball is a smooth white ball that can grow larger than a basketball in meadows, pastures and woodland edges in late summer and fall. Inside it is solid white, then turns olive-brown and powdery as the spores mature. Small specimens can be confused with deadly Amanita eggs.

A large, smooth white giant puffball among dark green leaves

The tell

A smooth white ball the size of a soccer ball or larger, solid and uniformly white inside with no trace of a cap, gills or stem.

Field marks

What to look at

Cap, underside and stem show in a photo. The spore print does not, and it is often the deciding check.

Cap
No separate cap. A smooth white ball or slightly flattened sphere with a soft, leathery skin, turning yellowish to brown and cracking open with age.
Underside
None. There are no gills or pores; the spores form inside the ball.
Stem
None. The ball sits on the ground, attached by a thin cord-like strand at the base.
Flesh
Firm, uniform and pure white when young, with a texture like marshmallow or tofu. It turns yellow, then olive-brown, and finally breaks down into powdery spores.
Spore print
Not taken; the mature spore mass is olive-brown.
Size
Usually 8 to 20 inches across (20 to 50 cm), sometimes larger.

Where and when

Where and when it grows

Habitat
Meadows, pastures, lawns, hedgerows and the edges of hardwood forests, often reappearing in the same spot each year.
Grows on
Soil, often rich ground with plenty of organic matter.
Season
Late summer through fall.
Range
Widespread east of the Rocky Mountains; western North America has a related giant puffball, Calvatia booniana.

Lookalikes

What the giant puffball gets confused with

Each card says how to tell the two apart.

  1. Compare side by side

  3. Western giant puffball

    Calvatia booniana grows in dry western sagebrush and grassland, and its skin breaks into large flattened warts instead of staying smooth.

Edibility

What the field guides say

Edible when pure white inside

Field guides list the giant puffball as edible only while the interior is firm and pure white throughout. Once the flesh turns yellow, olive or brown, guides record digestive upset. The main danger is confusion with the egg stage of deadly Amanita species, which contain amatoxins; these show the outline of a developing mushroom when cut in half, while a true puffball does not.

This page states what field guides record. It is not advice to eat, taste or handle anything, and a photo cannot settle edibility. If someone has eaten a wild mushroom that may be toxic, call poison control (1-800-222-1222 in the US) right away, before symptoms start: the deadliest species act hours later.

FAQ

Questions about the giant puffball

Are giant puffballs edible?

Field guides list them as edible while the inside is solid, pure white and uniform. Specimens that have begun to yellow or turn brown inside are past that stage and are recorded as causing digestive upset.

How do you tell a puffball from a poisonous mushroom?

Field guides describe cutting it in half from top to bottom. A true puffball is the same white all the way through. A young Amanita shows the silhouette of a cap, gills and stem inside, and an earthball is dark purple to black inside.

How big do giant puffballs get?

Most are 8 to 20 inches across, about the size of a soccer ball to a beach ball. Larger specimens are recorded, and a big one can weigh many pounds.

Sources

Where these facts come from

  1. Calvatia gigantea

    MushroomExpert.com

  2. Giant Puffball

    Missouri Department of Conservation

  3. Calvatia gigantea

    Index Fungorum

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