 The pores are slightly wider than long, so that there are about 9–10 pores per centimeter measured radially, but 12 to 13 per centimeter when measured tangentially, about halfway to the edge.As is the case with all boletes, spores form on the inner surfaces of the tubes and sift through their openings to be borne away on the air currents outside.The stem is by , roughly equal in width throughout, often crooked, and becomes hollow with age.