Natural hybridization has often been recorded within certain genera of orchids, one of them is Catasetum. During a field study in a forest de igapó in Brazilian Amazon, a new natural hybrid was found, it is here described as Catasetum × sheyllae. Its morphological features, mainly the structures of the lip, are intermediate between those of its putative parent species, C. boyi and C. garnettianum, both observed in sympatry.

This study describes a new natural hybrid of Catasetum, C. × vilhenense, from the State of Rondônia (Brazil) found in ombrophilous forests near the Roosevelt River. The hybrid shows intermediate morphological features between its parental species, C. ariquemense and C. multifidum, with specific differences in floral morphology and inflorescence structure. We provide detailed data on its habitat, ecology, and geographic distribution, and a photographic plate of the hybrid. Given its restricted range, limited to a single locality with an area of occupancy (AOO) of less than 10 km², C. × vilhenense may be Critically Endangered (CR) due to habitat loss and fragmentation. An identification key is also proposed for the species and natural hybrids of Catasetum with symmetrical and parallel antennae in the state of Rondônia, contributing to the understanding and classification of this genus in the Amazon forest.

Hybridization is a process that can occur randomly in nature between different genetically compatible species, as is observed within the genus Catasetum. Thus, this work proposes the description of a new nothospecies found in the lake of Castanho located in the municipality of Careiro Castanho. It is described, illustrated and compared with its parental species: C. gnomus and C. saccatum. In addition, information regarding the distribution, habitat and phenology as well as a key to the natural hybrids occurring in the Brazilian state of Amazonas are presented. Taxonomic notes are presented for five taxa of the genus currently treated as species that, after performing controlled pollination and germination in vitro, have proven to be in reality natural hybrids. Finally, we propose to place C. sanguineum into the synonymy of C. naso.

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.

This work aimed to prepare a nanoemulsion containing the essential oil of the Protium heptaphyllum resin and evaluate its biocidal activities against the different stages of development of the Aedes aegypti mosquito. Ovicide, pupicide, adulticide and repellency assays were performed. The main constituents were p-cymene (27.70%) and α-pinene (22.31%). The developed nanoemulsion showed kinetic stability and monomodal distribution at a hydrophilic–lipophilic balance of 14 with a droplet size of 115.56 ± 1.68 nn and a zeta potential of −29.63 ± 3.46 mV. The nanoemulsion showed insecticidal action with LC₅₀ 0.404 µg·mL⁻¹ for the ovicidal effect. In the pupicidal test, at the concentration of 160 µg·mL⁻¹, 100% mortality was reached after 24 h. For adulticidal activity, a diagnostic concentration of 200 µg·mL⁻¹ (120 min) was determined. In the repellency test, a concentration of 200 µg·mL⁻¹ during the 180 min of the test showed a protection index of 77.67%. In conclusion, the nanobiotechnological product derived from the essential oil of P. heptaphyllum resin can be considered as a promising colloid that can be used to control infectious disease vectors through a wide range of possible modes of applications, probably as this bioactive delivery system may allow the optimal effect of the P. heptaphyllum terpenes in aqueous media and may also induce satisfactory delivery to air interfaces.