Western 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 edible Calvatia sculpta differs in that it not as large (under 10 cm broad), has a short, thick pseudo-stem, and has a surface that is covered with large, sharply pointed, pyramid-shaped warts that are often somewhat hooked.

See also Calvatia gigantea.