The holm oak grows slowly, but, over the years, its forms abundant leafy foliage The leaves are small, coriaceous, dark green on the front and greyish-coloured on the reverse due to the short hairs covering them. Holm oaks are the most typical and developed schlerophyllic forests in the Mediterranean Basin, although, due to the formation of clearings by humans, pines are being introduced which are becoming the dominant species.

The acorns produced by the holm oak are a very important part of the diet of the Iberian pig, which gives us the delicious cured ham. It has been calculated that 10 kg of acorns eaten during the last 3 months of the pig's life are equivalent to 1 kg of Iberian cured ham.