The structural changes in the secretory cells are important to understand the ontogeny and nectar secretion process from the nectaries. In this study, we investigated the ultrastructural changes during different developmental/secretion stages of extrafloral nectaries (EFNs) of Pithecellobium dulce. The dense cytoplasm with active biosynthesis mechanisms such as ribosomes, mitochondria, large nucleus, and plastids with accumula...