Leaf anatomy of two medicinal Croton species: Contribution to plant recognition

Croton L. (Euphorbiaceae) is the second largest genus of the Euphorbiaceae s.l. family, which is composed of about 1,200 taxa. Several species are widely used medicinally in various parts of the world to treat cancer, digestive problems, skin diseases, malaria, ulcers, and obesity. The leaves and stems are sold as dehydrated fragments, or in powder form, and used in the preparation of teas and various types of formulations. The aim of this study was to accurately characterize the leaf anatomy of Croton bonplandianus Baill. and Croton gracilipes Baill. and to perform histochemical analysis of laticifers to provide subsidies for botanical certification. To accomplish this, leaf blade and petiole samples were fixed and prepared following standard techniques for scanning electron and light microscopy. Histochemical tests were carried out on sections to detect the compounds present in the secretions. Results showed neutral and acidic lipids, as well as phenolic compounds, in the latex. In addition, leaf anatomical structures of these two species were studied for specific identification of morphological characters and for quality assessment of these medicinal plants.