Of all the edible fungi, truffles are perhaps the most fascinating.  Truffles are the fruiting bodies (ascocarps) of mycorrhizal ascomycetous fungi. Unlike other common forest mushrooms, truffles spend the whole of their life cycle underground.  They resemble small pebbles or clods of dirt beneath the soil.

Truffles are not able to obtain the necessary substances for their development by photosynthesis, so they have to obtain those substances externally – in this case from the roots of certain plants (downy oak, poplar, linden, hornbeam, chestnut), setting up a process of symbiosis – the plant offering sugars and the truffle giving water and minerals in return. 

They have a vegetative part to them (micelio), made up of thin filaments (ife), whose job it is to absorb, so to carry out this function, the filaments are dispersed widely in the soil.  On contact with the roots of plants, these develop special organs (micorrize) by which the exchange of substances is carried out (described earlier).  The presence of these micorrize is vital for the development of the truffle. 

When the truffle is ready to be picked, it emanates a strong smell.  Wild boars, insects, slugs and rodents are attracted to this smell; they feed on the truffles and disperse the truffle spores , which pass through the digestive tract of these animals unscathed.  This is why it is common to find different types of truffle attached to the same ‘host’ plant.

Why all the prestige around truffles? Their scarcity, their indescribable, unique aroma and taste, the fact nobody knew for a long time how they grew. Prices are very high - currently at around €2,000 per kilo for the precious white truffle.