both of which are relict Saharan-Mediterranean species. Olive and myrtle trees grow at the bottom of wadis, intermittent stream valleys, or beside gueltas and permanent or temporary waterholes. Other species with a preference for moist habitats are Trianthema pentandra, Lupinus pilosus, and Convolvulus fatmensis. Silene kiliani, Acacia laeta, A. scorpiodes, and Cordia rochii grow in wadis. Other representatives of the 28 national Algerian plant rarities found on Tassili n'Ajjer include Ficus ingens and Anticharis glandulosa. Population and conservation The human population of the ecoregion is very small, with fewer than 5 persons per square kilometre. Many people are nomadic though some small cities also exist (such as Idlès). The vegetation remains fairly intact. References Deserts and xeric shrublands Ecoregions of Algeria Ecoregions of Mali Ecoregions of Mauritania Ecoregions of Niger Flora of Algeria Flora of Mali Flora of Mauritania Flora of Niger Geography of Mali Geography of Mauritania Palearctic ecoregions Tuareg