A puffball is a round fungus which bursts when it is ripe and sends a cloud of seeds into the air.
puffball in British English
(ˈpʌfˌbɔːl)
noun
any of various basidiomycetous saprotrophic fungi of the genera Calvatia and Lycoperdon, having a round fruiting body that discharges a cloud of brown spores when mature
puffball in American English
(ˈpʌfˌbɔl)
noun
any of various round basidiomycetous fungi (esp. order Lycoperdales) that burst atthe touch, when mature, and discharge a brown powder