From wiki

Geastrum triplex is a fungus found in the detritus and leaf litter of hardwood forests around the world. It is commonly known as the collared earthstar, the saucered earthstar, or the triple earthstar—and less commonly by the alternative species name Geastrum indicum. It is the largest member of the genus Geastrum (or earthstar fungi) and expanded mature specimens can reach a tip-to-tip length of up to 12 centimeters (4+3⁄4 in).

Shame they're inedible cos they look yummy