Summer Truffle Tuber aestivum Vittad. (illustrated 35% life size) Fruit body 3–7cm across, globose; blackish-brown; covered in pyramidal warts. Flesh whitish, becoming marbled grey-brown; taste nutty, smell sweet. Spores 20–40×15–30¼, ovoid, reticulate. Habitat buried, usually near beech on calcareous soils; summer to autumn, possibly all year (see note below). Rare, but it can be locally common. Edible good; I consider this to be as good as other European truffles. Note Dr Brian Spooner of Kew points out that two other truffle species should be considered. The rare T. brumale has spiny rather than reticulate spore ornament, and T. macrosporum (which is very rare in Britain) has similar fruit bodies, though with smaller surface warts, and its reticulate spores are much larger (45–75×30–50¼) than those of T. aestivum.
In the past this truffle was collected in quite large quantities, but it was thought to have declined and become a great rarity. Then in 2004 a farmer in southern England found large numbers (over 100) in a beech wood that he had planted 15 years before on very shallow, chalky soil. In the following year he again recorded it in considerable quantities, every month from February onwards.