In Piedmont, autumn is the season in which Tuber magnatum pico, the Alba white truffle, is gathered. This highly prized and scented underground fungus grows in symbiosis with the roots of some trees, notably oaks and poplars. It is hunted by dogs specially trained to sniff out its characteristic odour. When a dog locates a truffle, it starts scratching the soil with its paws and the truffle hunter, or tartufaio, eases out the fungus with a small hoe. The truffle is a refined, expensive delicacy, which is grated over many Piedmontese dishes. Truffle hunts are often carried out in the woods by night in the mist and the moonlight, all of which further enhances the charm of the Piedmontese autumn.