We report the first confirmed records of Catasetum arietinum F.E.L. Miranda & K.G. Lacerda in the state of Paraíba, north-east Brazil. According to the Flora e Funga do Brasil project, this species, of the Orchidaceae family, is endemic to Brazil, and was previously recorded only in the north-east, in the state of Pernambuco. Despite its restricted geographical distribution, the conservation status of this species has not been assessed. The new records are from the municipality of Lagoa Seca, c. 120 km from the state capital, João Pessoa.

The first record was in June 2015 in a fragment of humid Atlantic Forest on a large private cattle ranch. In the interior of north-east Brazil such forest remnants are known as Brejos de Altitude, montane humid forests occurring on plateaus, highlands and escarpments within the semi-arid region. These are fragments of mesophytic and hydrophytic diversity surrounded by a dry vegetation matrix, and are of high conservation value. However, they are under intense anthropogenic pressure, particularly from selective logging, agricultural expansion and real estate development. The second record was on a small private rural property c. 1 km from the first, in May 2025. This area is characterized by subsistence agriculture, with small-scale cropping and limited secondary vegetation remaining.

Only a single C. arietinum was found in each of the two localities, growing epiphytically in humid, shaded microhabitats. The few individuals found, combined with the lack of formal protection in these areas, raises concerns regarding the species’ local conservation status. Catasetum arietinum is poorly documented, with few specimens in national herbaria, and its geographical distribution is thus poorly known, which may reflect both actual rarity and a lack of surveys in suitable habitats. Given that the species is associated with humid Atlantic Forest remnants, there is a need to intensify surveys.

This new record of C. arietinum, in Paraíba, extends the known distribution of the species and highlights the importance of Brejos de Altitude as refuges for moisture-dependent species within the Brazilian semi-arid region. The occurrence of the species in both forest fragments and agricultural areas suggests a certain ecological tolerance, although likely constrained by specific microclimatic conditions. These findings emphasize the urgent need to expand botanical inventories in under-surveyed regions and to strengthen conservation efforts in areas potentially suitable for the species.

Catasetum arietinum recorded in May 2025 in the state Paraíba, showing (a) habit, (b) inflorescence and (c) details of flowers.