Capparis decidua is a xerophytic caper bush native to arid and semi-arid regions. It plays a crucial role in maintaining ecological stability and mitigating desertification. Characterizing the adaptive responses of C. decidua to contrasting ecological zones is essential for understanding its resilience and resistance to environmental stressors. Therefore, the identification of key structural and functional traits associated with survival strategies in differently adapted C. decidua populations was the focus. Ten naturally occurring populations of C. decidua from two distinct ecological zones, namely (1) barren and fertile areas and (2) saline and desertified regions, were selected. Populations inhabiting fertile environments exhibited an acquisitive growth strategy, characterized by larger plant size, increased biomass production, and enhanced shoot and root systems. Key anatomical adaptations included stems with larger areas, thicker pith, and extensive vascular bundles, facilitating efficient water and nutrient transport. Roots demonstrated increased cortical thickness and larger vascular bundles, optimizing nutrient uptake and water retention for competitive growth. Conversely, populations from saline and desertified regions displayed a conservative growth strategy, emphasizing survival under extreme conditions. These plants were smaller, with reduced morphological traits. Stems exhibited smaller areas, thinner cortex, and fewer vascular bundles, reflecting a resource conservation approach. Roots displayed reduced cortical thickness and smaller vascular bundles, minimizing water loss and limiting excess salt uptake. In conclusion, this research underscores C. decidua as a model species for understanding plant resilience and adaptive mechanisms in arid and semi-arid ecosystems. These findings have significant implications for biodiversity conservation, desertification control, and ecosystem restoration efforts.