 Relatively few boletes have an apical pore at the distal end of their basidiospores . The dark reddish @-@ brown , smooth spores of Porphyrellus amylosporus are truncate with a thin @-@ walled depression . Some species of Heimioporus have spores with apical pores , but molecular analyses demonstrate that Heimioporus is only distantly related to Spongiforma . 
