Anatomy and Histochemistry of the Vegetative System of Brachystele guayanensis (Lindl.) Schltr. (Orchidaceae), a Potential Medicinal Species

The orchid genus Brachystele Schltr. (Orchidoideae, Cranichideae, Spiranthinae) comprises 20 species distributed from Mexico to Argentina, with 10 found in Brazil. Anatomical studies of Orchidoideae Lindl. have been scarce, and the anatomy histochemistry are still largely unknown. In this study, we conducted a characterization vegetative organs B. guayanensis (Lindl.) using standard anatomical histochemical microtechniques. provide first information about Brachystele. studied was observed display characters commonly representatives Cranichideae tribe (e.g., uniseriate epidermis; homogeneous mesophyll 6–11 layers; rhizomes rings fibers; vascular bundles form “^” or “v”; fleshy roots velamen, simple trichomes, spiranthosomes). Others can be interpreted as adaptive strategies conditioned by environment their terrestrial life cuticle thickness; amphistomatic leaves; reduced velamen compared cortex (18–20 layers); raphides). cataphylls, presence spiranthosomes leaves, including stomatal guard cells, well alkaloids these structures, anatomically described for time Orchidaceae. hyphae pelotons stem is Cranichideae. Histochemical tests confirmed lignin, proteins, alkaloids, lipidic nature cuticle, starch grains stored spiranthosomes, composition raphides. Alkaloids were abundance, particularly roots, suggesting potential role defense against pathogens herbivores, medicinal activities, seen phylogenetically related groups