Bovista (A puffball)

The fruit body is a puffball that appears on the ground. Fruit bodies are more or less spherical and range from under a centimetre to 3 or 4 centimetres in diameter. The fruit bodies start off white but at maturity the colour is some shade of brown and there is an apical opening through which the spores escape. The skin of the fruit body is thin and flexible. Initially there is an additional flimsy outer layer, but much or all of this is shed by maturity, though you may see remnants as tiny granules or flakes (especially on the lower sides of a fruit body, where there is more protection against weathering).   

Specimens may appear at almost any time of the year and are often seen in groups, sometimes in densely packed clusters. This is genus that may show itself even in a hot summer, within a few days after rain, as tiny white balls. If the temperatures stay low the fruit bodies will develop fully. However, if the temperature rises soon after rain, development aborts and then it is common to see those white balls shrivelled or split.

Brief comments about other puffballs with well-defined apical openings:

Disciseda - The fruit body is a somewhat flattened sphere and soon after maturity has a soil case around the lower half  but that soil case will erode over time. You see several examples in this photo (https://www.anbg.gov.au/cgi-bin/phtml?pc=f&pn=453&size=3). The upper right specimen has been turned over.

Lycoperdon -  Mostly the fruit body has a noticeable pear-shape. The narrow part of that pear is a sterile base. In Lycoperdon a sterile base is well developed and looks and feels a bit like soft foam plastic. In Bovista such a sterile base is absent or rudimentary.