Gem-studded 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 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, lack spines, and have a black interior (though when very young, the interior is whitish). Other white puffballs include the not-recommended Lycoperdon marginatum and the edible Lycoperdon echinatum, both of which have spines that are long enough to join at the tips (1 mm to 6 mm long, respectively). The probably edible Lycoperdon curtisii differs in that it is smaller (under 2 cm broad) and has spines that are long enough to join at the tips, though the spines often fall away. Other white puffballs include Bovista plumbea and young specimens of Calvatia cyathiformis, both which lack spines and are edible when young and all-white. The edible, pestle-shaped Lycoperdon excipuliforme differs in that it is larger (to 15 cm broad) and lacks spines.