Giant Puffball

A number of potentially poisonous, white mushrooms are similar in appearance when they are in their immature button stage and lack a visible stem. Button stage mushrooms differ in that they are smaller (under 4 cm broad) and exhibit the faint outline of gills or other structures when cut in half, rather than having undifferentiated flesh. The poisonous earth balls (species of Scleroderma) are superficially similar, but are tan, yellowish or brown rather than white and have a black interior (though when very young, the interior is whitish). The similar-looking Lycoperdon pratense and other white puffballs differ in being much smaller. They are edible if the exterior is smooth and if the interior is all-white.

See also the edible Calvatia booniana, which differs in that the surface is covered in raised polygonal warts.