Diego Ferreira DA Silva

Summary: Dalechampia parvopseudantha (Euphorbiaceae), a new species with the smallest pseudanthium (2 – 2.5 cm long) within Dalechampia sect. Tiliifoliae , is described from the Atlantic Forest of Espírito Santo state in southeastern Brazil. The species is further distinguished by a combination of a 5 – 6 mm long peduncle; involucral bracts 1 – 1.5 × 0.7 – 0.8 cm, slightly 3-lobed, oblanceolate, yellowish-green, with a tomentose surface; staminate flowers with three broadly lanceolate sepals; sepals of pistillate flowers bearing conspicuous glandular trichomes and a stylar column with a slightly lobed apex. This unique set of morphological features readily distinguishes D. parvopseudantha from all other species of Dalechampia sect. Tiliifoliae , which is widely known to bear relatively large, up to 6.5 cm long pseudanthium. A full description, illustrations, field photographs, distribution map, phenology, habitat and a preliminary conservation status assessment are provided, as well as a table comparing the new species with its morphologically related, congeneric species. The striking size reduction of the pseudanthium discovered in a genus long used as a model for pollination biology, suggests that key ecologically informative variation may remain undocumented even in comparatively well-studied lineages.

The Amazon Basin is home to the world's greatest terrestrial biodiversity, but many plant groups remain poorly studied. One example is the mycoheterotrophic genus Thismia (Thismiaceae), which is notable for its highly specialized floral morphology and ephemeral life cycles, making it difficult to detect in the field and limiting its representation in scientific collections. Here, we report the first confirmed record of Thismia pseudomelanomitra in the Ecuadorian Amazon and expand its known distribution to the Brazilian State of Acre. Our study is based on a comprehensive review of herbarium specimens (AAU, RB, UFACPZ) and photographic records from iNaturalist.org . We also provide the first morphological description of its fruits and seeds, a distribution map, and an identification key for Ecuadorian species. Morphological comparisons reveal significant differences from related taxa, particularly T. melanomitra and specimens previously assigned to T. singeri . These findings highlight the role of citizen science and integrative approaches in documenting rare taxa and advancing conservation strategies.

A new species of Portulacaceae from the Amazonian savannas of northern Brazil is herein described and illustrated. Portulaca eggliana is morphologically related to P . umbraticola , but differs in the number of involucral leaves, sepal morphology, bracteole shape, and seed surface. Photographs, a line drawing, and notes on taxonomy, phenology, distribution, habitat, conservation status and etymology are also provided.

A remarkable new species of Anthurium, named A. petraeum, is here described. This new species is morphologically similar to A. sagrilloanum, differing in both vegetative and floral characters. Information on its distribution and habitat, preliminary conservation status, phenology and morphologically related species are given and photographs are presented.

Here a new record for Temnomastax beni is presented, a species previously known only for the type locality in Bolivia. The new record for Brazil, in Acre state, increases the geographic distribution of the species by 520 Km. Furthermore, it allows us to perform a better comparison with other species of the genus. An additional description of external morphology is presented, as well as the first description of the phallic complex.

Guapurium caipirinha (Myrtaceae) is a new species of jaboticaba from Minas Gerais state, Southeastern Brazil, which morphologically resembles Plinia oblongata, from which it differs in being a shrub or treelet 1–4 m height, with exclusively pentamerous flowers, and membranous epicarp with very sweet pulp. A detailed morphological description, etymology and vernacular names, information on history, phenology, conservation, habitat and taxonomic notes, a distribution map, and images of living plants and the type specimen are provided.

Peperomia (Piperaceae) is a pantropical genus comprising approximately 1700 species, primarily found in the Neotropics. The species are rupicolous, epiphytic, or terrestrial herbs that inhabit humid areas and, occasionally rupestrian fields. In this study, three new species of Peperomia, namely P. ilheusensis, P. itaimbense, and P. mendanhensis, belonging to the subgenus Multipalmata, are described from the Brazilian Atlantic Forest. The descriptions include detailed information, illustrations, distribution maps, and an identification key to species of P. subgen. Multipalmata in Brazil.

Peperomia (Piperaceae) is a Pantropical genus with approximately 1,700 species, distributed mainly in the Neotropics. In this study, three new species of Peperomia, P. bahiensis, P. ilheusensis and P. mendanhensis belong to subg. Multipalmata are described for the Brazilian Atlantic Forest. Detailed descriptions, illustrations, distribution maps and an identification key for the species are provided. Keywords: Rio de Janeiro, Bahia, Piperales, Neotropics.

Thismia violacea is described as a new mycoheterotrophic species discovered in an urban fragment semideciduous seasonal forest in the Brazilian Cerrado. Here we provide detailed morphological descriptions, with notes on the habitat, morphology, and a distribution map.

A new species of Thismia is described and illustrated for the Brazilian Amazon Forest. Thismia pseudomelanomitra belongs to Thismia subg. Ophiomeris sect. Pyramidalis and is morphologically similar to T. melanomitra. However, it can be recognized by its orbicular outer tepals with revolute margins, inner tepals connate over the tube opening forming a subglobose mitre, outer surface bearing prominent irregularly dentate ribs and irregularly foveae on top. The new species is known from a single locality, collected at São Nicolau Farm, in the northwest of Mato Grosso State. Herein, we provide a detailed description with illustrations, photographic plates, distribution maps, and preliminary conservation status.