As a step towards a revision of the sectional classification of Neotropical species of Habenaria, we focus here on section Pentadactylae. In its current delimitation, this is the largest of the 14 New World sections and embraces a group of 34 morphologically heterogeneous species. We expanded the sampling of Neotropical species currently placed in this section and performed Bayesian, maximum likelihood and parsimony analyses using nucleotide sequences from one nuclear (internal transcribed spacer, ITS) and three plastid (matK, trnK intron, rps16-trnK) DNA regions. In addition, morphological features of these species were reassessed. Based on our analyses, we propose that Habenaria section Pentadactylae should be recircumscribed to include only seven species: H. pentadactyla (the type species of the section), H. dutrae, H. ekmaniana, H. exaltata, H. henscheniana, H. megapotamensis and H. montevidensis. Thirty-two species previously assigned to the section grouped within unrelated clades and are therefore excluded from the section. There are no unambiguous morphological synapomorphies for the section, but the group can be confidently recircumscribed and identified on the basis of a combination of diagnostic morphological vegetative and floral characters. Morphological floral features in Habenaria montevidensis are distinct from those of other species in the section, probably as a result of a shift to diurnal pollinators. Following a taxonomic revision of the group, H. crassipes is placed under the synonymy of H. exaltata and neotypes are designated for H. crassipes, H. montevidensis and H. recta (= H. ekmaniana). All species in the section live in marshes or wet grasslands from northern Argentina to central Brazil; most species are concentrated in southern Brazil. Most species are probably rare, and five may be threatened according to the World Conservation Union (IUCN) criteria.

Four new species of Habenaria restricted to the Espinhaço Range in the states of Minas Gerais and Bahia are described: H. reflexicalcar, H. hippocrepica, H. quadriferricola, and H. espinhacensis. Specimens were collected as long ago as 1816, but they were misidentified or unidentified in herbarium collections. Molecular phylogenetic analyses based on nuclear and plastid DNA sequences showed that these species form a highly supported clade, denominated Espinhacenses, which is related to other species having linear, grass-like leaves that are concentrated in the cerrado and campos rupestres vegetation of central and southeastern Brazil, although the closest relatives to the Espinhacenses clade were not resolved. There are no apparent morphological synapomorphies for the clade, it being characterized by a combination of characters, including slender plants, linear leaves, spiral inflorescences, few to many small and glabrous flowers, a pedicel that is shorter than the ovary, and separate hemipollinaria.

Melioidosis, a severe infectious disease caused by Burkholderia pseudomallei that is prevalent in Southeast Asia and Northern Australia, has been sporadically reported in Brazil since 2003. We report a case of aortic aneurysm with blood culture positive for B. pseudomallei. The phylogenetic analysis of 16S ribosomal DNA showed this isolate to be evolutionarily grouped with the MSHR346 strains from Thailand.

Habenaria bicornis fue descrita por primera vez en 1835, para Cuba, y era conocida apenas para este país y unos pocos registros de Panamá, de 1920. En el presente estudio, demostramos que H. bicornis y H. goyazensis, esta última conocida para Brasil y Guiana, son específicas y la especie se distribuye desde México hasta el sudeste de Brasil. El modelado de nicho y la recolección de datos indican que esta especie posee una preferencia por sabanas húmedas de tierras bajas y es predicho que su distribución incluye gran parte del Neotrópico con hábitats favorables. Los análisis filogenéticos moleculares con secuencias del ADN nuclear (ITS) y plastidial (matK) ubicaron H. bicornis en una posición aislada próximo a la base del clado Neotropical, aunque con bajo soporte. En términos de su morfología, sus relaciones no están aclaradas, ya que no hay similitudes evidentes entre H. bicornis y los subclados básales o cualquier otro subclado Neotropical. Los análisis citogenéticos indican un número cromosómico básico de x=21, similar a las otras especies basales del Neotrópico.

A Serra da Canastra está localizada no sudoeste de Minas Gerais e situa-se dentro do domínio do Cerrado. Os estudos florísticos na região começaram na década de 1990, mas ainda estão incompletos e Orchidaceae é uma das famílias que não foram estudadas. Neste trabalho é apresentado um inventário do gênero Habenaria na Serra da Canastra. Foram registradas 28 espécies para a região, sendo que H. canastrensis e H. pseudoculicina são endêmicas restritas a área de estudo. A Serra da Canastra, com 30% do total de espécies registradas para Minas Gerais é uma das cinco unidades de conservação com maior diversidade do gênero no estado. Ocorrem na área de estudo principalmente espécies de ampla distribuição, bem como algumas espécies típicas do planalto central e outras típicas do Espinhaço, mas nenhuma espécie típica dos campos de altitude do domínio da Mata Atlântica. Palavras-chave: Cerrado, inventário florístico, taxonomia. AbstractThe Serra da Canastra is located in the southwestern part of Minas Gerais within the Cerrado Biome. The floristic studies of the region began in the 1990's but are incomplete and Orchidaceae is one of the families that were not studied yet. This work presents a survey of the genus Habenaria in Serra da Canastra. 28 species were recorded for the region, two of which, H. canastrensis and H. pseudoculicina, are endemics from the study area. 30% of the Habenaria recorded for Minas Gerais occur in Serra da Canastra and the area is one of five conservation units with the highest diversity of the genus in the state. In the study area occur mainly species with broad distribution, as well as some species typical of the central plateau or typical of the Espinhaço range, but none species typical of high altitude grasslands of the Atlantic Forest domain.