BOLETUS  , a well-marked genus of

fungi (order Polyporeae), characterized by the central stem, the cap or pileus, the soft, fleshy tissue, and the vertical, closely-packed tubes or pores which cover the under surface of the pileus and are easily detachable . The species all grow on the ground, in woods or under trees, in the early autumn . They are brown, red or yellow in colour; the pores also vary in colour from pure white to brown, red, yellow or green, and are from one or two lines to nearly an inch long . A few are poisonous; several are good for eating . One of the greatest favourites for the table is Boletus edulis, recognized by its brown cap and white pores which become green when old . It is the ceps of the continental European markets . There are forty-nine British species of Boletus .