Geastrum triplex - probably the commonest earthstar but still infrequently found. This species usually occurs in woodland litter. During the early stage of development the fruit body is more or less spherical but as it matures the outer part (the periderm) splits open to form the characteristic rays. The expansion of the rays helps to lift the fruit body clear of the litter layer. The spores are liberated by rain splash through the pore visible in the centre of the fruit body. This type of fungus is related to the mushrooms and toadstools but differs in an important respect since the reproductive cells are formed inside the fruitbody. In comparison, the reproductive cells of the mushrooms and toadstools are formed externally (e.g. on the surface of the gills).