Although its straight silhouette with drooping branches is fairly uniform and easily identifiable, the appearance and antlers of the common spruce (Picea abies) vary according to altitude, climatic conditions, and age. The upright twigs of young trees thus hang like drapes in older individuals. The spruce's long and persistent needles are renewed within five and a half years and live from five to seven years. A vast spruce forest surrounds the shores of Lake Servières, perched at an altitude of 3,937 ft (1,200 m) in the Puy-de-Dôme department.