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In Tunisia, the rehabilitation of overgrazed and degraded rangelands is being attempted through the reintroduction of various native perennial plant species. We studied plant-water relations in two of the leading candidate species, Seriphidium incultum (syn: Artemisia herba-alba) and Anthyllis henoniana, under conditions of water stress. Anythyllis was found to be adapted to water stress water reserves lying deep in the soil. In contrast, Seriphidium has adapted to drought by tolerating very severe desiccation of its above-ground parts. Moreover, Seriphidium individuals consists of several hydrologically independent subunits, with the result that one part of the plant can die without damaging the rest of the plant. Relationships between xylem potential in the two species and soil water potential are also discussed.