Ilex aquifolium (European Holly) is a hardy tree, capable of surviving in most conditions except where it is extremely wet. Large circular groves of holly trees tend to form in the wild and the New Forest in Hampshire is one such location where they can be found. In Britain and many other western cultures, holly is most often associated with Christmas. As it is an evergreen, Ilex aquifolium makes an ideal festive decoration, along with its bright red berries. Holly is rarely used medicinally due to its toxicity, but is diuretic, relieves fevers and has a laxative action. It contains saponins, the xanthine theobromine and a yellow pigment ilexanthin. Ilexanthin is obtained in the following manner. The leaves are exhausted with alcohol, the alcohol is distilled off, and the residue set aside for several days. A sediment forms, which is separated from the mother liquor, treated with ether to remove the chlorophyll, and then purified by repeated solution in alcohol and crystallization. Yellow pigment of the leaves of Ilex Aquifolium, scarcely present during winter, but copiously in the hotter part of the summer.