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.

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.

In the present study we propose a new Catasetum taxon belonging to the group of species with symmetrical and converging antennae. It was found in a vegetation of “terra firme” and “campinarana” in the central Brazilian Amazon. A detailed description of the taxon is given as well as a photograph plate and comments relating to distribution, habitat, phenology and conservation status. It is compared to C. rivularium and C. barbatum which are sympatric species and somewhat similar to the new taxon. Furthermore, we present a key to Catasetum species with symmetrical and convergent antennae occurring in the Brazilian Amazon.

This study presents a new orchid species of the genus Catasetum belonging to the group of species with symmetrical and parallel antennae. It was found in terra-firme and floodplain forests in the Brazilian states of Amazonas and Pará. We provide a formal description of the new species, images, and notes on distribution, habitat, phenology, flower visitors and preliminary conservation status. We compare it with C. cristatum and C. barbatum, both sympatric and morphologically most similar to the new species. It was preliminarily classified in the Endangered (EN) category according to IUCN criteria based on the extent of occurrence, area of occupation, number of occurrence locations and the risks that the known populations are exposed to (deforestation and predatory collection).