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The bark of the underground stem of Tontelea micrantha (Mart. ex. Schult.) A. C. Sm., a native Brazilian Cerrado species, is used in folk medicine for treating kidney ailments. The structures of the underground and the aerial stems were examined and their barks were analyzed for the presence of secondary metabolites. Bark fragments were processed according to conventional techniques in plant anatomy and their chemical compositions examined using histochemical and phytochemical tests, thin layer chromatography, and high-efficiency liquid chromatography. The underground stem is a sobol with unusual cambial activity. Laticifers that secrete terpenoids were present in the cortex and phloem of both organs and can contribute to the identification of the species in field. Druses were present in both barks, but mono-crystals were only observed in the sobol. Tannins, flavonoids, alkaloids, and terpenoids occurred in both types of bark, but carotenoids were only detected in the sobol. The similarities between these two organs indicate that the aerial stem bark has potential medicinal use and represents a plausible alternative to harvesting the sobol, which could contribute to the preservation of natural populations of this species.

Leaf glands are common structures in Malpighiaceae and exhibit great morphological diversity, yet information on their anatomy, secretion and type of visitors remains scarce. Th e aim of this study was to describe the distribution, anatomical development and chemical and functional properties of leaf glands of Banisteriopsis muricata (Malpighiaceae). Leaves at diff erent stages of development were collected and processed according to standard techniques for light and scanning electron microscopy. Secretion composition was determined by histochemical tests and test-strips, while gland funciton was determined by fi eld observation of interactions with visitors. Leaf glands were located on the petiole and on the abaxial base of the leaf blade. Th e gland secretion was found to be a protein-rich nectar that was foraged upon by ants (Solenopsis); it was found accumulated in subcuticular spaces without pores or stomata for its release. Leaf glands were found to develop from protoderm and ground meristem, and consisted of typical secretory epidermis, nectariferous parenchyma and vascularized subnectariferous parenchyma. Th erefore, it can be concluded that the distribution, chemical nature of secretion and anatomy of leaf glands of B. muricata characterize them as EFNs, while foraging by ants indicate a mutualistic relationship that possibly protects the plant against herbivores.

Th is study aimed to anatomically characterize the extrafl oral nectaries (EFNs) of annatto (Bixa orellana) and determine the composition of its nectar in order to better understand their structure and function during organ development. Standard light and scanning electron microscopy techniques were used for anatomical analysis, and test-strips and a refractometer for determining nectar composition. Both receptacle and stem EFNs were found to possess similar anatomy and nectar composition, and to secrete from early to advanced developmental stages of the organs to which they are associated. EFNs consisting of uniseriate epidermis, nectariferous parenchyma and subnectariferous parenchyma were found located where vascular tissue is immersed. Some layers of nectariferous parenchyma exhibited sclerifi cation and cells with phenolic compounds or calcium oxalate druses were present. Nectar exuded by stomata was acidic, diluted and found to contain sugar. Th e anatomical and histochemical features of annatto EFNs ensure their integrity and nectar secretion function during the development of buds, fl owers and fruits.

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