Pear-shaped, yellowish brownish puffball with a pore at the top. Grows in large clusters on decaying wood. July–November. Fruiting body pear-shaped; outside yellowish to brownish; inside pure white; surface with tiny warts; base attached to wood by strands of mycelium. When mature, a pore opening at the top releases spores. Spore print olive brown. Spores magnified are round, smooth.
Lookalikes: Pigskin puffball (Scleroderma citrinum) is brownish; inside it is dark brownish purple. Gem-studded puffball (L. perlatum) is white with dense spiny warts; it fruits on the ground (not on wood). Some other mushrooms, including the deadly destroying angel (Amanita bisporigera), have young "button" stages that resemble puffballs. Make sure you cut through puffballs from top to bottom to confirm they are pure white inside, like a marshmallow, with no sign of a developing cap or stem.