Tuber magnatum

[2] It is found mainly in the Langhe and Montferrat areas[3] of the Piedmont region in northern Italy and, most famously, in the countryside around the cities of Alba and Asti.

[4] Acqualagna, in the northern part of the Marche near Urbino is another center for the production and commercialization of white truffles, and its annual festival is one of the most important in Italy.

[14] Less commonly, they are associated with five other species of host plants, each from different genera: Abies alba (conifer), Alnus cordata, Fagus sylvatica, Pyrus pyraster and Ulmus minor.

The warmest mean air temperature for WT growth in Jun–Aug is 24.3 °C (99th percentile), about four degrees above the physiological optimum for mycelial development in soil; temperatures in excess of this limit reduce the amount of mycelium in the topsoil (on about 10 cm); this may explain why T. magnatum develops extra-radical mycelium in soil horizons below 30 cm.

But T. magnatum is less tolerant than T. melanosporum and T. uncinatum (Burgundy truffle) of short-term precipitation deficits in summer because its peridium is not as well developed, thus subjecting the ascocarp to more water transpiration than in these two other species.

The ongoing climate change, with expected precipitation increase and projected warming, is likely to bring further north the present northernmost limit of its range and expand it into central and western Europe.

[14] On the other hand, temperatures increase in humid continental climates (such as central Europe and the interior of the Balkan Peninsula) is likely to bring in more precipitations and subsequent floodings.

The alluvial/riparian habitats of T. magnatum would then be subjected to excessive waterlogging and overall inundations, which would interfere with the development of mycorrhizae and the formation of fruitbodies, as demonstrated by the Burgundy truffle elsewhere.

One of the largest truffles found in decades, it was unearthed near Pisa, Italy, and sold at an auction held simultaneously in Macau, Hong Kong, and Florence.

Tuber oligospermum, that grows well in Tunisia's dry sand and not deemed of any culinary value in Italy, is sold as T. magnatum.

In 2017, Italy's financial police, the Guardia di Finanza, uncovered a €66 million tax fraud among truffle producers.

T. magnatum also assimilates/accumulates Cu, K, Na, P, and Zn more efficiently than these other species; on the other hand, T. brumale was more successful in assimilating/accumulating S.[26] But carbon isotope signatures of the various truffle species cannot discriminate their geographical origins, because mycorrhizal fungi are enriched in 13C compared to their host trees (fungi receive up to 20% of the total carbon fixed by their host trees), and forest ecosystems are characterized by settings that are too complex to allow for such discrimination.