 Astraeus hygrometricus is an ectomycorrhizal fungus and grows in association with a broad range of tree species . The mutualistic association between tree roots and the mycelium of the fungus helps the trees extract nutrients ( particularly phosphorus ) from the earth ; in exchange , the fungus receives <unk> from <unk> . In North America , associations with oak and pine are usual , while in India , it has been noted to grow commonly with <unk> pine ( Pinus <unk> ) and <unk> ( <unk> <unk> ) . The false earthstar is found on the ground in open fields , often scattered or in groups , especially in nutrient @-@ poor , sandy or <unk> soils . It has also been reported to grow on rocks , preferring acid substrates like slate and granite , while avoiding substrates rich in lime . In Nepal , fruit bodies have been collected at elevations of 3 @,@ 000 m ( 9 @,@ 800 ft ) . Fruit bodies typically appear in autumn , although the dry fruit bodies are persistent and may last up to several years . <unk> <unk> is a <unk> fungus with minute , gelatinous , <unk> ( cushion @-@ shaped ) <unk> , known to grow only on the inner surface of the rays of dead Astraeus species , including A. hygrometricus . 
