Phylogenetic analyses of early-diverging Faboideae have indicated that genera previously positioned in distinct tribes are instead closely related, e.g. in the Amburaneae clade, and the relatively recent rearrangements of many genera into clades has hampered the identification of morphological synapomorphies for previously unrecognized clades. Our aims are to evaluate anatomical vegetative characters of leaflets attached to reproductive features in the Amburaneae clade, to identify new synapomorphies for the clade and subclades, to identify characters supporting intergeneric relationships and diagnostic characters for the genus and species and to provide information about the morphology and histochemistry of secretory structures. The study was based on the anatomy of the leaflet of 19 species of the Amburaneae clade. Papillae cells, the presence of vascular system units and hypodermis are shared features of Amburaneae. Anatomical characters of the leaflet can be diagnostic at the generic and specific levels in Amburaneae. Secretory structures found in the clade are secretory cavities, secretory channels, idioblasts, mucilaginous epidermal cells and glandular trichomes. The broader concept of Amburaneae is reinforced here by morphological and molecular data, with the identification of new synapomorphies. Our dataset supports the intergeneric relationships resolved by molecular data.

The historical background of studies on Brazilian Orchidaceae dates back almost 400 years. In this review, we provide an overview of the current knowledge on Brazilian Orchidaceae across three thematic axes: 1. diversity, distribution, and endemism; 2. taxonomy and systematics; and 3. structural, genetic, and ecological characterization. Brazil harbors five naturalized and 202 native genera, of which 23 are endemic to the country. There are currently 2515 accepted species (out of 9907 species names). Among the 7218 synonyms, 3915 are heterotypic, yielding a synonymy rate of 60.9%. Brazil is the second country in orchid endemism with 1540 endemic species. Apostasioideae is not present in Brazil, but the remaining four orchid subfamilies are represented by 16 tribes and 23 subtribes. The richest phytogeographic domain is the Atlantic Forest (1398 spp.), followed by the Amazon Forest (784 spp.) and Cerrado (656 spp.). The richest subtribes are Pleurothallidinae (642 spp.), Laeliinae (397 spp.), and Oncidiinae (283 spp.). Moving beyond a purely taxonomic and phylogenetic framework, this work offers a comprehensive synthesis of Brazilian Orchidaceae, encompassing the state of the art in cytogenetics, anatomy, population genetics, reproductive biology, and pollination. Despite these advances, there are pronounced disparities among regions, taxa, and research approaches. The persistence of these shortfalls highlights the urgent need for integrative research frameworks. Future progress in Brazilian orchidology depends on the strengthening of collaborative networks and interdisciplinary approaches.

The secretory structures of Alismataceae have been described as secretory ducts, laticifer ducts, laticifer canals or schizogenous ducts. However, these terms are not found in the specialized literature, and ontogenetic analyses for the exact classification of these structures are missing. Accordingly, more studies regarding the secretory structures of Alismataceae are necessary to establish homology in the family or in the order. Thus, the aim of this study was to describe the anatomy, ontogeny, distribution in the organs and exudate composition of the secretory structures present in five Alismataceae species in order to determine whether the family has laticifers or secretory ducts. Samples of leaves, flowers and floral apices were processed for anatomical and histochemical analyses by light microscopy. The analysis indicated the presence of anastomosing secretory ducts in all species, occurring in both leaves and flowers. The exudate contains lipids, alkaloids, proteins and polysaccharides, including mucilage. The secretory duct structure, distribution and exudate composition suggest a defense role against herbivory and in wound sealing. The presence of secretory ducts in all species analyzed indicates a probable synapomorphy for the family.