With the onset of a bit of rain and cold, mushroom foraging season has started in France. Many people restrict themselves to the Bolete family (ceps, porcini and relatives) because they are easy to recognise and it's difficult to make yourself sick with this family (and virtually impossible to kill yourself). There are a few species that will make you sick but in the Touraine they are very rare (I've only encountered one once) and they are so luridly coloured they are not appetizing at all. Several species are not toxic, but so bitter that you don't want to eat them anyway. A quick tongue test in the field will sort these out. Many species turn blue when cut. This is not an indication of toxicity -- in fact a couple of the species eaten regularly here turn a thoroughly unappetizing blue, through to black when cooked or dried.
A mushroom in the Boletaceae family (Suillus sp),
showing the characteristic tubes and spongey pores underneath.
Boletes are a safe bet in the forest if you are foraging. Few are toxic and none are deadly. Just make sure your mushrooms have tubes and pores underneath, like this one, not gills. That is your diagnostic for ceps, porcinis and other boletes. (This one is actually a type of Slippery Jack Suillus sp, which I would recommend peeling, and in any case isn't a terribly interesting mushroom to eat -- but it clearly shows the tubes and the spongey layer of pores on the underside.)
The key to identifying Boletes is that they do not have gills (like a supermarket mushroom), they have tubes and pores. The pores form a spongey layer over the tubes under the cap. Other families of mushrooms have pores, but they don't have the tubes so until you get your eye in it is worth breaking your mushrooms to reveal the tubes, just to be sure.
A pair of mushroom foragers encountered in the forest recently.
If you have gathered some boletes and are still worried about eating them I suggest drying them. You can completely dry them and store them in a jar for later reconstitution, or slice them and lay them out to dry over night. Then cook them hard for a couple of minutes, tip off the liquid they release, then continue cooking for a couple more minutes. Either of these methods will remove possible toxins. Do not eat wild mushrooms more than once a week, as many species are bioaccumulators and you may find you are consuming radioactive or heavy metal elements in unwise quantities.