Calophyllaceae in Brazil is represented by 7 genera and 96 species, including trees, subshrubs, shrubs, and some lianas, characterized by the presence of ducts and cavities responsible for the production of bioactive substances. Although investigations exist on these structures in adult leaves of K. rubriflora, there are still gaps to be filled. Thus, this study aims to investigate the ontogeny of the ducts, the distribution pattern, the main metabolites of the secretion, and the influence of rocky outcrops in the Amazonian savanna on the density and lumen area of ​​the ducts. Samples of shoot tips with leaf primordia and leaves at different stages of development were collected from three distinct substrates in the rocky Amazonian savanna in Nova Canaã do Norte. The samples were processed at the State University of Mato Grosso (UNEMAT), Alta Floresta campus, using standard anatomical methodologies. The ducts of K. rubriflora develop from the fundamental meristem in a schizogenous manner, being located below the epidermis, in the cortical parenchyma, close to the phloem and in the central parenchyma. The descriptions of the anatomical characteristics of K. rubriflora are consistent with previous studies. Based on histochemistry, we observed lipophilic and hydrophilic substances. Regarding the influence of rocky outcrops, we observed variations in the density and size of the duct lumen. We conclude that anatomical studies of K. rubriflora leaves are essential to understand its adaptive strategies and taxonomic delimitation within the Kielmeyera complex. The metabolites found play crucial roles in the plant's protection and resistance, and the variations in the ducts reinforce the idea that the environment directly influences the anatomy of the leaf ducts.