Lycoperdon perlatum

Lycoperdon perlatum, popularly known as the common puffball, warted puffball, gem-studded puffball or devil's snuff-box, is a species of puffball fungus in the family Agaricaceae. It is a medium-sized puffball with a round fruit body tapering to a wide stalk, and dimensions of 1.5 to 6 cm (1⁄2 to 2+1⁄4 in) wide by 3 to 10 cm (1+1⁄4 to 4 in) tall. It is off-white with a top covered in short spiny bumps or "jewels", which are easily rubbed off to leave a netlike pattern on the surface. When mature it becomes brown and a hole in the top opens to release spores in a burst when the body is compressed by touch or falling raindrops.

Common puffball, releasing spores in a burst by compressing the body