Truffle

Truffle is practically the name of all subterranean fungi that are used for food. The truffle of English markets is Tuber aestivum, one of the Ascomycetes. It grows under beech oak birch or (rarely) conifers, on clayey or calcareous soil; from July to November, and is black with polygonal warts externally, and brown with white veins internally. Its fragrant smell can often be detected in woods, and dogs are trained to grub it up. Its market value is two or three shillings a pound, It being inferior to the French truffle. This species (T. melanosporum) is more globose, browner externally, and blacker internally. It is a winter species, and is to some extent cultivated, the ground under oak-trees in Poitou and Southern France being watered with the spores. The French crop is worth £800,000 per annum. It is this species that is employed in the pate de foie gras de Perigord. The Italian or Piedmontese Truffle (T. magnatum) is paler in colour and garlic~scented. The potato-like African Truffle., (Terfezia leonis) also occurs in Italy. On the Continent swine are trained to hunt truffles. The rarer White Truffle (Chaeromyces meandriformis) is sometimes sold in England; as are also the worthless "Red Truffle" (Melanogaster variegatus) and "False Truffle" (Scleroderma vulgare), which are puff-balls, ie. Gasteromycetes, and not truly truffles.