About this fungus
Brain Puffball is a fungus in the Agaricaceae family. Its habitat and field characteristics are summarised below.
A large puffball with a rounded to skull-like outline and a thick sterile base. It begins smooth and white to tan, then develops deep folds and wrinkles that create its distinctive brain-like appearance.
What to check
Examine the whole fruit body and make a lengthwise cut when checking an immature specimen. A true young puffball has a uniform, firm white interior with no outline of a cap, gills, stem or other structures. Any internal mushroom outline, dark tissue or developing structures means it is not a suitable match. There is no ring or volva on a true puffball.
Variation
The outer surface changes from smooth and pale to wrinkled, folded and tan or brown. Inside, the firm white spore tissue matures through yellow-green or olive to a dry powdery mass. The pronounced brain pattern may be weak in young fruit bodies.
Lookalikes
Calvatia cyathiformis and other large puffballs can overlap in size and shape but develop differently coloured mature spore masses. Earthballs have a tough rind and dark interior. Young Amanita buttons can be white outside but reveal a developing cap, gills and stem when cut lengthwise, which is why the internal structure check matters.
Habitat and range
Saprotrophic on soil in open woodland, forest edges, lawns, fields and other grassy ground. It is recorded from North America and parts of Asia and Australia. Regional range and mature spore characters help separate it from other large Calvatia.
Food safety
Edible.
Use this profile to learn what to examine and compare, not as proof that a mushroom is safe to eat. Check the whole specimen and every important lookalike before reaching an identification.
Species to compare
Similar mushrooms to compare against: