The "white truffle" or "trifola d'Alba Madonna" ("Truffle of the White Mother" in Italian) (Tuber magnatum) is found mainly in the Langhe and Montferrat areas[26] of the Piedmont region in northern Italy and, most famously, in the countryside around the cities of Alba and Asti;[27] Acqualagna. Growing symbiotically with oak, hazel, poplar and beech and fruiting in autumn, they can reach 12 cm (5 in) diameter and 500 g, though are usually much smaller. The flesh is pale cream or brown with white marbling.[24] Italian white truffles are very highly esteemed (illustration, left) and are the most valuable on the market.

Source: Wikipedia