 Young specimens of C. geaster have a hollow , club @-@ shaped dark @-@ brown fruit body , connected to a stem . The stem , which is usually buried in the ground , is shorter than the hollow fruit body or equals it in length , although the stem length is somewhat variable depending on the depth of the underground root to which it is attached . The flesh of the stem and the wall of the fruit body is white , while the inner surface is yellowish @-@ white , turning light brown with age . The fruit body varies in width from 1 @.@ 2 to 3 @.@ 5 cm ( 0 @.@ 5 to 1 @.@ 4 in ) in the thickest portion , and has a length of 4 to 12 cm ( 1 @.@ 6 to 4 @.@ 7 in ) ; the stem is 0 @.@ 75 to 1 @.@ 5 cm ( 0 @.@ 3 to 0 @.@ 6 in ) wide by 1 to 5 cm ( 0 @.@ 4 to 2 @.@ 0 in ) long . Both stem and fruit body are covered by a dense layer of soft brown velvety " hairs " , or tomentum . In maturity , the fruit body splits open into 4 – 7 rays that curve downward , similar to mushrooms of the genus Geastrum . The spores are borne on the inner surface of the rays , which , depending on the maturity of the specimen , may range in color from whitish to saffron to salmon to butterscotch to chestnut . The leathery rays are up to 0 @.@ 35 cm ( 0 @.@ 1 in ) thick . 
