"Chicory flowers are the sky mirror. That is why it is said that, when we contemplate the blue of its petals, our sight calms down and our spirit elevates itself." (in "Uma mão cheia de plantas que curam", Fernanda Botelho)
Common chicory is a plant of the dandelion family with beautiful blue flowers (for curiosity, it's the cousin of the cultivated endives). It lives as a wild plant on roadsides and other weedy places in its native Europe, India and Egypt, and has travelled and established itself in North America, China, and Australia.
It's a very nourishing plant: its mineral-rich leaves can be eaten in salads (along with the flowers, for the color), containing sugars and inulin, as well as vitamin B, C, P and K. They are very bitter, so better consumed when young.
However, it's in the the roots that we find the more powerful medicinal properties. They are commonly used as a coffee substitute, but in the roasting process they lose most part of its properties. If consumed as an herbal decoction, the chicory roots are very rich in pectin, tannins, sugars, and, most important, inulin, a healthful prebiotic. Prebiotics are natural substances that we find in certain vegetables. Our intestinal flora loves them, as they nourish the good bacteria. To benefit from it, you can reduce the roots into a powder, and put it in salads, soups, oatmeal,...
Chicory is also depurative, stimulating biliary functions: it helps our body detoxify. Galien, a famous doctor of the Roman Empire, used to say that it was a "liver-friendly" plant. It is not, however, the most effective, if compared with rosemary or dandelion.
These "liver-friendly" plants are usually also very helpful to solve skin problems (these two organs, along with the kidneys, are responsible for waste elimination of the body). This said, it can be a very useful ally for treating chronically skin problems like acne, eczema or redness.