Boletus is a genus which covers over 100 species of mushrooms; this group is reminiscent of the Agarics because they both have caps and stems but the difference lies in what is under the caps. Instead of gills the mushrooms of this group have a layer and tubes and pores which are packed tightly together. The spores are stored in these tubes until they are discharged. Within this group the physical characteristics of the mushrooms vary drastically, this makes them difficult to identify and categorize.