<p>Leaf shape variation and bilateral symmetry have been extensively studied using geometric morphometrics, yet most analyses focused on homologous landmarks on leaf outlines, while internal anatomical structures, such as leaf venation, remained comparatively understudied. In this study, we therefore focused on how the shape of major vein intersections relates to the overall leaf shape in a model dataset from field maple (<i>Acer campestre</i> ). The patterns of symmetric shape variation, fluctuating asymmetry (FA), morphological integration, and modularity were studied, combining analyses of leaf outlines with homologous landmarks on leaf lobes, sinuses, and major vein intersections. Procrustes ANOVA revealed that symmetric variation among individual leaves and trees dominated overall shape variation in all datasets, whereas no significant directional asymmetry was detected. In contrast, FA was pronounced and statistically significant at the level of individual leaves for both outline-based and fixed landmark-based datasets. Analyses of morphological integration demonstrated considerable differences among the datasets. The outlines showed a moderate level of global integration above the level of self-similarity, whereas the fixed landmark configurations, representing lobes and especially vein intersections, were strongly disintegrated. Modularity tests further supported the hypothesis that leaf margins and venation branching constitute distinct developmental modules, a pattern that was even more pronounced when analyses were restricted to FA components. These results indicate relative developmental independence of venation branching from overall leaf shape and suggest that parallel analyses of external and internal leaf structures might provide complementary insights into developmental processes and environmental responses in plant leaves.</p>