What are some tips for identifying edible boletus mushrooms?

Most edible boletus mushrooms feature a two to 10-inch cap that is smooth and becomes sticky when the weather gets wet. The cap starts out convex but becomes flatter when the mushroom matures. The young caps are denser, while the older ones are spongy.

The mushroom itself has a pleasant aroma, and the flesh is dense and white. The spores of the mushroom are an olive brown color. The pores are white or yellowish when the mushroom is young, changing to pea green when it gets older. The stem of the mushroom is very thick and is either white or reddish brown.