Ascomata: hypogeous, subglobose, lobed, with basal cavity often penetrating inside the gleba, 1-4 cm in size, covered with a thick, reddish brown, cottony tomentum.
Gleba: hard, solid, whitish at first, then yellowish gray, greenish gray, grayish brown, darker at maturity, marbled with two kinds of numerous, branching veins: the one kind dark-coloured, thin and not always clearly visible, contain no air (venae lymphaticae, veines aquiferes of Tulasne, venae internae of Vittadini), the other white, broad and often radiating from the base, conveying air (air-veins, veines aeriferes, venae externae).
Taste: faint, like sunflower seeds.
It is a Mediterranean species, of warm places and not widespread. They usually ripen in in autumn and winter, although you can find them year-round. We harvest them under holm oaks, in calcareous soils, in sunny places, often sharing habitat with Tuber aestivum and Tuber nitidum in June and July. Tuber panniferum inhibits plants growing and makes “burns”.
This species is identified macroscopically without any difficulty because of the woolly felted tomentum
Asci: subglobose, short-stalked, 70-90 x 60-70 µm excluding stalk, 1-8-spored (usually 6-7-spored).
Ascospores: 20-26 (40) x 16-23 (30) µm excluding ornament, size variable depending on number of spores in the ascus, Q range = 1,11-1,33, broadly ellipsoid, yellow, translucent, ornamented with conic spines, separate, 2-3 µm long.
Peridium: 250-300 µm thick, pseudoparenchymatous, composed of subglobose cells in the outermost layers, covered with a woolly tomentum of brown, thick-walled hyphae.