Boletus aereus

Boletus aereus.
Boletus aereus, the dark cep, is a prized edible mushroom in the family Boletaceae. It is widely consumed in Spain, France, Italy, Greece, and generally throughout the Mediterranean. Described as a new species in 1789 by French mycologist Pierre Bulliard, it is closely related to several other European boletes, including B. reticulatus, B. pinophilus, and the popular B. edulis. The fungus predominantly grows near broad-leaved trees and shrubs in symbiosis with the roots, enveloping them with sheaths of fungal tissue. Quercus suber, the cork oak, is a key host. The spore-bearing mushrooms appear above ground in summer and autumn, growing a large dark brown cap, up to 30 cm (12 in) in diameter. Like other boletes, B. aereus releases its spores through pores on the underside of the cap instead of gills; this surface is whitish when young, aging to a greenish-yellow. The squat brown stalk, up to 15 cm (6 in) tall and 10 cm (4 in) thick, is partially covered with a raised network pattern.