Fleshy cap and stalk mushrooms with pores.
Basidiomycota > Class Agaricomycetes > Order Boletales.

Boletales contains most of the Boletes spread among 5 families but it also contains many true gilled
    mushrooms and others of varying shapes.
Boletes are common mushrooms which have features of both gilled fungi (fleshy cap and stalk) and
    polypore fungi (downward pointing tubes under the cap).

Most form symbiotic relationships with tree roots.

The stem may be club shaped or short and spherical.
It is large and thick in relation to the cap.

The upper part of the stem is covered with a fine raised network or reticulum.
The lower part of the stem is smooth or ridged.
It may be white or coloured.

The young cap is convex with the edge turned downwards.
It flattens with age and can grow to a diameter of 35 cm.
The cap may be red, white, brown or grey.

The under surface of the cap has a spongy appearance being made up of vertical tubes which open on
    the surface as pores.

When young the surface is pale and the pores are difficult to see but they become apparent as the
    mushroom matures and the layer darkens.

The pore layer is attached to the top of the stem.
It cannot be removed without causing damage, unlike true gills which are easy to remove.

Porcini mushrooms are boletes.