 Boletus abruptibulbus is a species of bolete mushroom in the family Boletaceae . Described as new to science in 2009 , it is found only in the Gulf Coast of the Florida Panhandle , where it grows on the ground in coastal sand dunes , one of only three North American boletes known to favor this habitat . The fruit bodies have convex brownish caps up to 8 cm ( 3 @.@ 1 in ) in diameter , supported by solid yellowish to reddish stems measuring 3 – 5 cm ( 1 @.@ 2 – 2 @.@ 0 in ) long by 10 – 15 mm ( 0 @.@ 4 – 0 @.@ 6 in ) thick . The pores on the underside of the cap measure about 1 – 2 mm in diameter and are initially pale yellow before developing a greenish tinge in age . The mushroom 's spores , about 20 micrometers long , are unusually long for a member of the Boletaceae . The stem base is bulbous , a diagnostic feature for which the species is named . 
