Flora in the Sierra Norte de Sevilla Natural Park
Vegetation in the Sierra Norte de Sevilla Natural Park is for the most part indigenous, and therefore totally adapted to the hot, dry summers and relatively mild winters. The most characteristic species of tree are the holm and cork oak, dotted all over the rolling hills and flat plains, and offering a certain amount of shade in summer. Near Constantina there is an impressive wood of gall oaks, as well as the only specimens of Pyrenean oak in the province of Seville.
Of the vast number of plants that have been catalogued in the Natural Park, there are over 20 types of orchid, and if the Sierra Norte de Sevilla is combined with that of Aracena in nearby Huelva, 2,000 of the 2,500 types of fungus found in Andalusia (the most diverse European region) are located here.
The thinness of the soil on the open plains and the hot summer temperatures has meant that plants are necessarily hardy and do not require high humidity. Varieties include lavender, rock roses, thyme, Spanish broom and gorse.
The river banks of the three rivers that flow through the Natural Park have their own specific vegetation, quite distinct to that of the open plains and hills. The most common species of tree are the elm, willow, alder and ash.