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). A number of other white puffballs differ in being much smaller. Such puffball are generally edible if the exterior is smooth and if the interior is all-white. The edible Lycoperdon excipuliforme is white when young and can be up to 15 cm broad; it differs in that it is pestle-shaped.