The flora in the Tibesti is Saharomontane, mixing Mediterranean, Sahara, Sahel and Afromontane vegetation. Biodiversity and endemism levels are much higher in the Tibesti than in the Aïr Mountains or the Ennedi Plateau, although the vegetation's coverage is highly dependent on rainfall. A number of oases lie along the courses of the enneris such as Enneri Yebige, which is virtually unexplored. These oases, which are more numerous to the north and west of the range, have vegetation of the genera Acacia, Ficus (fig trees), Hyphaene and Tamarix. Most gueltas are lined with macrophytes including Cyperus laevigatus, Equisetum ramosissimum, Juncus fontanesii and Scirpus holoschoenus. Acacia nilotica grow near these water basins. Myrtus nivellei and Nerium oleander grow between elevations of in the western part of the range, while Tamarix nilotica grow at similar elevations in its northern part. Downstream, where the current of the enneris is slower and the riverbed is deeper, there are dense thickets of Tamarix aphylla and Salvadora persica (locally known as yii).