text: amanita aestivalis amanita aestivalis , commonly known as the white american star - footed amanita , is a species of fungus in the amanitaceae family of mushrooms . 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 , 5 to 8 . 5 cm ( 2 . 0 to 3 . 3 in ) in diameter and white . it sits atop a stem that is 8 . 5 to 16 cm ( 3 . 3 to 6 . 3 in ) 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 of the genus amanita , a grouping of amanitas characterized by having spherical spores , well - developed rings , weakly reddening flesh , and " " ( 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 5 to 8 . 5 cm ( 2 . 0 to 3 . 3 in ) 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 discolored tissue colored brownish - red shades . sometimes , the edge of the cap has radial grooves — up to 4 mm ( 0 . 16 in ) long — that mirror the position of the underlying gills . when moist , the cap is sticky to the touch ; when dry , it is shiny , usually without any remnants of the thin volva . the white gills are crowded close together , and are free from attachment to the stem . they are : slightly swollen in the middle , and tapering near the ends . the stem is 8 . 5 to 16 cm ( 3 . 3 to 6 . 3 in ) long by 0 . 9 to 1 . 6 cm ( 0 . 4 to 0 . 6 in ) thick , and slightly thicker at the base than at the top . it is stuffed with whitish hyphae that resemble cotton . the surface of the stem is smooth or has delicate tufts of soft , white , woolly hairs . there is a rimmed bulb at the base of the stem , which can reach a diameter of over 3 cm ( 1 . 2 in ) . the ring — located on the upper portion of the stem , 1 . 2 – 1 . 7 cm ( 0 . 47 – 0 . 67 in ) from the top — is white , membranous , and long - lasting . the volva remains closely attached to the bulb , although a portion may stretch out like a thin membrane and adhere to the base of the stem before collapsing . the flesh will slowly turn pinkish - brown to chocolate - brown when it has been injured or bruised . young specimens do not have any distinct odor , but fruit bodies may smell slightly of onions or garlic in age . although the edibility has not been documented for this species , some sources have noted that toxicity is suspected . microscopic characteristics viewed in deposit , like with a spore print , the basidiospores of a. aestivalis are white . examination with a microscope reveals further details : they are roughly spherical , hyaline ( translucent ) and thin - walled , with dimensions of 7 . 8 – 8 . 8 µm . the spores are amyloid , meaning that they will absorb iodine when stained with melzer 's reagent and appear blue to blackish - blue . the spore - bearing cells , the basidia , are four - spored , thin - walled , and measure 32 – 60 long by 4 – 13 µm thick . there are no clamps present at the bases of the basidia . similar species according to singer , the species is often mistaken for a. verna in the eastern united states . a. verna , however , has ellipsoid spores . other white amanitas within the range of a. aestivalis include the deadly toxic species a. virosa ( has a more loose cottony stem ) , a. phalloides ( the cap usually has an olive - green tint ) and a. bisporigera ( typically has two - spored basidia ) . a. aestivalis is sometimes considered a white form of a. brunnescens , but this latter species has dusky brownish gray radial stripes and usually has many fibrils ( short section of hyphae ) projecting from the surface , to produce a fine , hairy appearance . further , it stains more rapidly than a. aestivalis . a. ( the " european star - footed amanita " ) is cream to yellow color , and differs from a. aestivalis in its reaction to chemical tests . it is only known from europe . habitat , distribution , and ecology amanita aestivalis is a mycorrhizal species , meaning it forms a mutualistic relationship in which the vegetative hyphae of the fungus grow around and enclose the tiny roots of trees and shrubs . in this way , the plant is better able to absorb phosphorus and other soil nutrients , while the fungus receives moisture , protection , and nutritive byproducts of the plant 's metabolism . fruit bodies of the fungus grow on the ground in deciduous , coniferous , and mixed forests . a preference has been noted for oak woods containing tsuga or pinus species , as well as beech wood with picea , abies , and betula . fruit bodies typically appear from late june until autumn . in north america , it has been found in the states of new england , as well as alabama , new york , and virginia . the distribution extends north to the southeastern provinces of canada and south to florida .