Synonyms: Lycoperdon aestivalis Bonord.
Fruiting body 1.5-3.0 (4.0) cm broad, globose to pulvinate, attached to the substrate by one or more root-like rhizomorphs; exoperidium persistent, white, at first tomentose-subflocculose, soon breaking up into buff to tan-tipped areolae or fine warts, with age exposing an ochre-brown to medium-brown, glabrous, papery-thin endoperidium; spores released via a ragged apical pore; gleba soft, white, soon yellowish-olive to olive-brown, medium-brown at maturity; subgleba present or absent, if present, a thin layer of compact tissue, appearing cellular only with a handlens; odor and taste not distinctive.
Spores 3.5-4.5 µm , globose, moderately thick-walled, smooth to faintly warted, with a central oil droplet and stub-like pedicel; capillitium from the central part of the gleba of the "intermediate" type, with numerous minute pits.
Solitary, scattered, or in small groups on edges of grassy areas, disturbed ground, e.g. vacant lots, along paths; also found in coastal dunes among herbs and shrubs; fruiting where watered during the summer months and throughout the fall and winter after periods of rain; common but inconspicuous.
Edible, but too small to be of culinary value.
Bovista aestivalis is one of several, small, round puffballs found in the coastal regions of California. It is most likely to be confused with Bovista dermoxantha which has a similar peridium and is also rooted. The two species are best told apart microscopically, Bovista aestivalis possessing an "intermediate" type of capillitium (see image) with abundant minute pores, and nearly smooth spores, while B. dermoxantha has a "Lycoperdon" type capillitium with numerous variable-sized pores and spores that are slightly roughened. Another mimic of Bovista aestivalis is Bovista plumbea. It is often common in grassy areas but can be told apart by a glabrous exoperidium when young, a grey endoperidium at maturity, and typically the lack of a rooted base. Less likely to be confused is Bovista pila, which although rooted, is distinctly larger, the fruiting body opening irregularly, usually by large cracks or splits. Species of Scleroderma, "Earthballs," bear a superficial resemblance to the above, but can easily be distinguished by a thick peridium and purple gleba at maturity.