White, rounded to turban-shaped ball with spiny warts and a pore at the top. Grows on the ground. July–October. Fruiting body rounded to turban-shaped with an elongated base; outside white, becoming yellowish to pinkish to brownish; inside pure white, becoming brownish dust; outside covered with spiny, detachable warts, especially dense at the top; when mature, a pore opens at the top to release thick, dusty spores. Spore print olive brownish. Spores magnified are elongated, stalklike.
Lookalikes: Pigskin puffball (Scleroderma citrinum) is brownish; inside it is dark brownish purple. Pear-shaped puffball (L. pyriforme) is brownish, with a smoother surface, and grows on wood. Some other mushrooms, including the deadly destroying angel (Amanita bisporigera), have round, "button" stages that look like puffballs. Make sure you cut through all puffballs, top to bottom, to confirm they are pure white inside, like a marshmallow, with no sign of a developing cap or stem.