Amanita aestivalis, commonly known as the white American star-footed amanita, is a species of fungus in the mushroom family Amanitaceae. The fungus is distributed in the eastern United States, south to Florida, and reaches north into the southeastern provinces of Canada. The cap of the fruit body is medium-sized, in diameter and white. It sits atop a stem that is long and has a rounded bulb at its base. The entire fruit body will slowly stain a reddish-brown color in response to bruising or aging. It remains unknown whether Amanita aestivalis is a distinct species from A. brunnescens, another similar Amanita with a comparable distribution. There are several other white-bodied amanitas with which A. aestivalis may be confused, including A. virosa, A. phalloides, and A. bisporigera. Taxonomy, classification, and naming American mycologist Rolf Singer first described the species in 1949 based on specimens he had collected in Massachusetts, Michigan, New York and Virginia. Because this original report was published without a Latin description (contrary to the naming conventions of the International Code of Botanical Nomenclature), he later amended his description in 1959. There is some doubt as to whether A. aestivalis is a distinct species from A. brunnescens (the "brown American star-footed Amanita"), as described by George F. Atkinson in 1918. Singer claimed that the latter species could be distinguished from the former by the consistent absence of dusky brownish-gray radial stripes on the cap. However, in 1927, mycologist Louis Charles Christopher Krieger described the variant A. brunnescens var. pallida, which he said was identical to A. brunnescens except for the white or very pale cap. In his 1986 monograph on North American species of Amanita, David T. Jenkins preferred to reserve judgment on the matter. Amanita aestivalis is classified in the section Vallidae of the genus Amanita, a grouping of amanitas characterized by having spherical spores, well-developed rings, weakly reddening flesh, and "limbate" volvals (with narrow "limbs" protruding from a soft, margined bulb). The specific epithet is derived from the Latin adjective aestivalis, meaning "pertaining to the summer". Its vernacular name is the "white American star-footed Amanita". Description The cap of the fruit body is in diameter, and depending on its age, may range from egg-shaped to convex to somewhat flattened. Older specimens may have edges that are curved upwards. The color is white or pale tan in the center of the cap; older specimens may have areas of