The red radicchio of Treviso is familiar to most people as that slightly bitter purple leaf in many Italian salads, a type of chicory.

The Italian for the distinct flavor of 'radicchio rosso di Treviso' is 'amarognolo' .

There are two types of radicchio from Veneto.

The 'rosso di Treviso' and the 'variegato' from Castelfranco Veneto.

The former comes in the form of spear shaped red leaves with a white crunchy stem while the latter is similar to a large flower sometimes known as the 'fiore che si mangia'.

They are cultivated with great care in environmentally controlled conditions and nothing as unpredictable as the sun or rain is allowed to interfere with their growth.

They are surprisingly versatile as a vegetable and can be cooked in a number of ways, noy least in a good risotto with gorgozola cheese.

Some restaurants even created whole menus based on the radicchio.

The best even have a trademark, the 'Indicazione Geografica Protetta' or (I.G.P.).

Try this recipe for roast duck and celery featuring radicchio.

From the Consorzio tutela Radicchio Rosso di Treviso e Variegato di Castelfranco, we learnt the following:

The Radicchio Rosso di Treviso is very much part of local rural tradition and this particular strain first began to appear in the middle of the sixteenth century.

Rather like rhubarb, the red radicchio is 'forced' in a dark environment depriving the plant of all or almost all its chlorophyll pigments.

This brings out the intense red colour of the leaf as well as a certain crunchiness.

The leaves of the Radicchio Rosso di Treviso can grow straight upwards to a height of 20 centimetres.

The tips of the leaves tend to fold in towards each other and enclose the tuft .

As well as the province of Treviso the vegetable is cultivated in parts of Padua and Venice.