The fruitbody consists of a cap atop a central stem. Below the cap, instead of gills, there are pores. The fruitbody has a fleshy texture.
Species of Boletus come in a variety of sizes and colours and may be dry or have a viscous coating - it depends on the species. When damaged, the pores or flesh may or may not undergo a colour change. Once again, it depends on the species.
There is neither a universal nor a partial veil.
You may at times be fairly confident of recognizing a specimen of Boletus in the wild. However, to be sure you have a species of Boletus (rather than a bolete of some other genus) a look under the microscope may be necessary.
Boletus sp. is listed in the following regions: