T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network

Calvatia gigantea (Giant puffball)

Kingdom: Fungi
Phylum: Basidiomycota
Class: Agaricomycetes
Order: Agaricales
Family: Agaricaceae
Genus: Calvatia
Species: C. gigantea
Binomial name: Calvatia gigantea
Synonyms: Langermannia gigantean, Lycoperdon gigante
Common name: Giant puffball

Giant puffballs (Calvatia gigantea) occasionally turn up on farmland and deciduous forests usually in late summer and autumn. It is found in temperate areas throughout the world. The largest can grow to over 1 metre in diameter but usually grow to be 10 to 50 centimetres in diameter. 
The fruiting body of this puffball will develop within the period of a few weeks and then it will begin to decompose and rot.
When young they are white inside. As they age the outer skin turns yellow and the interior turns into a mass of greenish brown spore dust. Large specimens can easily contain several trillion spores. The spores are dispersed by the wind when the skin decays.

A mature giant puffball whose outer skin has started to decay.

The out skin as rotted away leaving the spore mass which will dry and be dispersed by the wind.

Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0/