Article

The southern limit of peat mosses (genus Sphagnum) in the western Mediterranean basin is located in North Africa, where they are rare and restricted to a few wet habitats. Based on herbarium specimens from 1861 to 1958, on recent collects and on floristic surveys, the present paper addresses the taxonomy, distribution, and ecological significance of peat mosses of the Numidian-Kroumirian range. Despite 17 different names are mentioned in the literature and on herbarium specimens, only two species (Sphagnum auriculatum and S. subnitens) are attested in Numidia and Kroumiria. However, S. subnitens, only known from collects in 1948 and 1951 in Kroumiria, is considered as regionally extinct. S. auriculatum still occurs in several sites on Jbel Bir and Jbel Sra in Kroumiria, and in El Tarf region in Numidia, but it seems to have disappeared from Senhadja and El Kala regions (Algeria), and from Sejenane region (Tunisia), at both extremities of its ancient distribution area. It develops mainly within shrubby communities, often comprising Alnus glutinosa and Erica scoparia, and belonging to the regressive hydroseral series of the Alnion glutinosae. It constitutes a characteristic species of the pioneer stage of the succession, corresponding to the association Cariceto-Sphagnetum (plumulosi) auriculati. The present-day decline, along with the rarity and vulnerability of Sphagnum and associated species in Numidia and Kroumiria should lead to the rapid protection of their habitats, which are threatened of complete disappearance on the short term.