1911 Encyclopædia Britannica/Boletus

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.