HADIDI, RihabHAFSI, Zakaria2024-11-112024-11-112024http://dspace.univ-skikda.dz:4000/handle/123456789/3351This present study provides an overview of the specific complex Crataegus oxyacantha L., hawthorn in Algeria, whereby the phenotypic variability of its leaves was studied at both intra- and inter-population levels using quantitative and qualitative morphological characters. It appears that the Algerian formations of this species seem to be rapidly sliding towards intense and progressive degradation due to strong anthropogenic and environmental pressures. Subsequently, following the statistical analysis of the data, the analysis of variance for the quantitative variables studied concerning the leaves revealed significant differences at both intra- and inter-population levels. This variability is primarily justified by abiotic pressures, i.e., limiting geographical and climatic factors or gradients that exert a significant influence (grouping of the two sampled populations via factorial analysis). These factors are linked to continentality and even aridity under the influence of environmental components. At the same time, other biotic factors have also been reported, including the presence of hybridization phenomena produced by ornithochory. Consequently, the data obtained during this study confirm that: • The studied Algerian populations seem to exhibit morphological variation (studied phenotypic characters) that is not clear and remains to be discussed. • Phenotypic variation among different populations helps understand the resistance and adaptation of this species to environmental constraints. In perspective, it emerges that the variability of Algerian populations of the specific complex C. oxyacantha is still largely to be discussed, which should encourage us to address other taxonomic traits (flowers, pollen, roots, etc.) and why not in other forest stations, particularly those in the Algerian coastal or continental environment.frMémoire de Master