The milk thistle or sheep thistle (Silybum marianum) is the thistle par excellence. It is a very vigorous annual or biennial herb, which can reach two meters in height and be dominant in the thickets where it is installed. It has rigid leaves with a characteristic marbled white reticulum on the obverse, very large leaves on the basal rosette and amplexicaules on the upper part of the stem, all of them lobed and with each lobe ending in a more or less sharp spine. They are also very characteristic chapters as artichokes, with purple flowers, which appear at the beginning of summer. Each of the bracts of the involucre of this flower head ends in a triangular appendage, curved outwards, sharp and rigid, especially vulnerable. Its flower appears in the warm months, with the arrival of spring and until mid-summer. Milk thistle grows in soil altered by man or his domestic animals, whose soils are deep, nitrogenous and not too dry. The ground fruits of milk thistle and its leaves cut to remove thorns have a tradition of use in herbalists. This species originates from the Mediterranean and Asia Minor, although it is now more widespread. Given its long list of properties, milk thistle is used as a natural remedy in the treatment of a wide range of ailments: empachos and intoxications, treatment of hepatitis, cirrhosis or other liver damage, seasonal allergies, reduce blood sugar levels, has anti-inflammatory and diuretic properties, menstrual odors and has anti-inflammatory and diuretic properties.