Hygroscopic Earthstar
Hard-skinned Puffball
Astraeus hygrometricus
Photographed near Yarnel, Arizona in July 2004.
Upon maturity the outer layer of this puffball mushroom splits open to produce a star-like structure. The central pore emits spores when the body is bumped or jostled.
These mushrooms are commonly found in the Upland Sonoran Desert and into chaparral habitat. The tough outer cortex that forms the star is tough enough to persist for some years.