Brazil is known as a center of diversity for several plant families. Among these, Acanthaceae are especially diverse in the Cerrado, which is home to ca. 150 species, many of which are endemic. Recent field and herbarium studies of Ruellia of the Cerrado in Goiás and Distrito Federal have led to the discovery of 9 species new to science, which we formally describe as R. altoparadisensis, R. cataractae, R. ceciliae, R. chapadensis, R. glandulifolia, R. hatschbachii, R. lucindae, R. mellosilvae, and R. pinguicula. In addition to botanical illustrations, we provide information about their geographical distributions, habitats, phenologies, and preliminary conservation status. Species are discussed in the context of the Cerrado physiognomies and sub-biomes, which are delimited. We additionally propose one new combination (R. rosmarinus), two lectotypifications (R. pohlii and R. adenostachya), and an identification key to Ruellia species that occur Brazilian Cerrado.

A new species of Heuchera (Saxifragaceae) from western North Carolina is described and illustrated herein, including phylogenomic and morphological analyses of its closest allies in the Heuchera parviflora group. Heuchera tuckasegeensis is distinguished from the other Heuchera taxa based on its distinct morphological attributes (style and stamen length, petiole and laminar hair length, and degree of leaf lobing), phylogenetic position, habitat preferences, and edaphic substrate specialization.

The genus Justicia (Acanthaceae) is represented by 12 species in the Mexican portion of the Yucatan Peninsula (MYP), one of which, Justicia cardinalis, is herein proposed as new to science. The new species is known from sub-xerophytic or seasonally dry forests over calcareous, rocky soils along the northern and northeastern regions in the MYP. This taxon has been confused with J. carthagenensis for more than 100 yr, but there are remarkable differences between the two taxa. The new species has linear to narrowly obovate (vs. oblong-spathulate to spathulate) floral bracts and narrower leaves. The corolla is red with white markings in the lower lip (vs. purple with white markings on the central lower lip and the upper lobes), and the corolla tube is as long as the lobes, whereas it is shorter than the lobes in J. carthagenensis. We provide relevant visual resources to aid in the identification of the new species. The conservation status is preliminarily assessed as Least Concern (LC) using the B criteria of the IUCN. Furthermore, we provide a brief synopsis, a distribution map, and a key to the species of Justicia from the MYP (as well as photographs of most of them). Finally, to be able to apply the names in an unambiguous manner, we designate a lectotype and an epitype for J. carthagenensis, and a lectotype for J. spicigera.

Two new species of Christisonia (Orobanchaceae), Christisonia hekouensis Gui L.Zhang, J.D.Ya & W.B.Yu and Christisonia dentosa J.D.Ya, Gui L.Zhang & W.B.Yu, found during botanical surveys in Southeast Yunnan, China, are described and illustrated. The two new species are similar to C. kwangtungensis bearing rose-red flowers and conspicuously inflated corolla tubes, and phylogenetic analyses strongly support the three species as monophyletic. However, C. hekouensis can be distinguished from C. kwangtungensis and C. dentosa by having externally puberulent calyces and corollas, corolla lobes with serrulate margins, styles that are pink and glabrous or sparsely capitate-glandular pubescent above, and with anthers less than 2 mm below the stigma. Christisonia dentosa differs from C. kwangtungensis and C. hekouensis by having dentate corolla lobe margins, internally capitate-glandular pubescent corollas, styles distinctly capitate-glandular pubescent above, and more than six anthers which are up to 10 mm below the stigma.

The diverse and spectacular Hibisceae tribe comprises over 750 species. No studies, however, have broadly sampled across the dozens of genera in the tribe, leading to uncertainty in the relationships among genera. The non-monophyly of the genus Hibiscus is infamous and challenging, whereas the monophyly of most other genera in the tribe has yet to be assessed, including the large genus Pavonia. Here we significantly increase taxon sampling in the most complete phylogenetic study of the tribe to date. We assess monophyly of most currently recognized genera in the tribe and include three and thirteen newly sampled sections of Hibiscus and Pavonia, respectively. We also include five rarely sampled genera and 137 species previously unsampled. Our phylogenetic trees demonstrate that Hibiscus, as traditionally defined, encompasses at least 20 additional genera. The status of Pavonia emerges as comparable in complexity to Hibiscus. We offer clarity in the phylogenetic placement of several taxa of uncertain affinity (e.g. Helicteropsis, Hibiscadelphus, Jumelleanthus, and Wercklea). We also identify two new clades and elevate them to the generic rank with the recognition of two new monospecific genera: 1) Blanchardia M.M.Hanes & R.L.Barrett is a surprising Caribbean lineage that is sister to the entire tribe, and 2) Astrohibiscus McLay & R.L.Barrett represents former members of Hibiscus caesius s.l. Cravenia McLay & R.L.Barrett is also described as a new genus for the Hibiscus panduriformis clade, which is allied to Abelmoschus. Finally, we introduce a new classification for the tribe and clarify the boundaries of Hibiscus and Pavonia.

We reexamine the taxon Spiranthes stylites, currently synonymized under S. australis, finding multiple lines of evidence from molecular phylogenetics, phenology, morphology, and habitat differences to support its distinction from other members of the Spiranthes sinensis species complex. Compared to its closest relative S. australis, S. stylites blooms earlier (June – early July vs. mid July – September), has consistently white tubular flowers (vs. commonly pink and pseudocampanulate), a distinctly long-clawed labellum (vs. shortly clawed), slender labellum nectar callosities (vs. globose), a proportionally larger column foot (ca. 50% of the length of the entire column vs. ca. 25%), and occurs in closed canopy woodlands (vs. open graminoid habitats). Spiranthes stylites is the only Spiranthes in the Eastern Hemisphere to have a woodland habitat. The recognition of S. stylites helps support white colored flowers as the plesiomorphic and most common floral condition in the complex, and indicates pink colored flowers likely arose independently in S. australis and S. sinensis s.s.

The genus Burmeistera consists mostly of cloud forest species occurring from Guatemala to Peru. Molecular work on this group has revealed previously established subgeneric groupings to be non-monophyletic, while also identifying several monophyletic groups with recognizable synapomorphies. One such monophyletic group is a clade of species with recurved corolla lobes which contains three species: B. crispiloba, B. sodiroana, and B. succulenta. As many as nine names have been recognized previously for these species, though the most recent taxonomic treatments recognize only these three. Additional collections of these species made in the last forty years have uncovered phenotypic variation showing that characters traditionally used to differentiate them no longer do so clearly and suggest the possibility of introgression between them. Here, we report morphometric analyses of herbarium specimens of the recurved corolla clade, using both hierarchical and normal mixture model-based clustering methods to test the current species hypotheses. Our results support the recognition of the three known species plus the newly described Burmeistera kitrinaima sp. nov. We provide complete descriptions of all four species, and include photographs, distributions maps, taxonomic discussion, and an identification key.

El género Burmeistera consiste principalmente de especies de bosques de neblina desde Guatemala hasta Perú. Trabajo molecular en este grupo ha revelado que los grupos subgenéricos previamente establecidos no son monofiléticos, además ha identificado varios grupos monofiléticos con sinapomorfías reconocibles. Uno de estos grupos monofiléticos es un clado de especies con lóbulos de corola recurvados que contiene tres especies: B. crispiloba, B. sodiroana y B. succulenta. Hasta nueve nombres se han reconocido previamente para estas especies, aunque los tratamientos taxonómicos más recientes reconocen únicamente estas tres. Colecciones adicionales de estas especies realizadas en los últimos cuarenta años han descubierto variación fenotípica demonstrando que los caracteres tradicionalmente utilizados para distinguir entre especies ya no lo hacen de manera clara, y sugieren la posibilidad de introgresión entre ellas. Aquí, reportamos análisis morfométricos de especímenes de herbario del clado de corola recurvada, utilizando los métodos de agrupamiento jerárquico y de modelos de mezcla normal para evaluarlas hipótesis actuales de especies. Nuestros resultados respaldan el reconocimiento de las tres especies conocidas, además de una nueva especie recién descrita Burmeistera kitrinaima sp. nov. Describimos las cuatro especies en detalle e incluimos fotografías, ilustraciones, mapas de distribución, discusión taxonómica y una clave de identificación.

Oxalis sect. Holophyllum (Oxalidaceae) is a small group of species that is endemic to the Brazilian Atlantic Forest in the states of Rio de Janeiro, Minas Gerais, Espírito Santo, and Bahia. Species of the section can be recognized by their unifoliolate leaves, one-seeded carpels, and the common presence of dorsiventrally flattened (and sometimes winged) peduncles and/or petioles. Circumscriptions of the currently accepted species needed to be revaluated, as the overlap in several features have blurred limits among morphologically similar taxa. In this study we evaluate the monophyly and phylogenetic relationships among species of O. sect. Holophyllum, and provide an updated taxonomic study of the section, aiming at improving species circumscriptions and facilitating species-level identification. For this task, we analyzed samples from herbaria and carried out fieldwork to observe the plants in loco, collect samples, and gather material for DNA extraction, amplification, and sequencing. Bayesian and maximum likelihood phylogenetic analyses were performed using sequences from three markers: nrITS, and plastid trnL-trnF, and petA-psbJ from 13 of the 17 currently accepted species, which corroborate the monophyly of the section. Among the species of O. sect. Holophyllum, ten are newly described here at species level: O. adpressipila Fiaschi & Bilk (based on O. kuhlmannii Lourteig var. adpressipila Lourteig), O. capixaba Fiaschi & Bilk, O. cornicarpa Fiaschi, O. inopinata Fiaschi & Bilk, O. itamarajuensis Fiaschi & Bilk (based on O. alata Mart. ex Zucc. var. hirta Lourteig), O. leonii Fiaschi & Bilk, O. occulta Fiaschi & Bilk, O. retrorsa Fiaschi & Bilk, O. sciophila Fiaschi & Bilk, and O. septentrionalis Fiaschi & Bilk. Lectotypes are chosen for nine names, and an epitype for O. impatiens Vell. An identification key to all species is provided, as well as descriptions, illustrations, geographic distribution maps, and preliminary conservation statuses following IUCN guidelines.

Oxalis sect. Holophyllum (Oxalidaceae) é um pequeno grupo de espécies endêmicas à Mata Atlântica dos estados do Rio de Janeiro, Minas Gerais, Espírito Santo e Bahia. Espécies da seção podem ser reconhecidas pelas folhas unifolioladas, carpelos unisseminados, e geralmente pela presença de pedúnculos e/ou pedicelos achatados dorsiventralmente ou, às vezes, alados. As circunscrições das espécies atualmente aceitas precisam ser reavaliadas, já que a sobreposição observada em vários caracteres mascara limites entre táxons morfologicamente similares. Neste estudo nós investigamos o monofiletismo e as relações filogenéticas entre espécies de O. sect. Holophyllum e fornecemos uma atualização taxonômica da seção, com o intuito de aprimorar as circunscrições das espécies e facilitar a sua identificação. Para atingir esses objetivos, nós analisamos amostras de herbários e conduzimos expedições a campo para observar as plantas in loco, coletar amostras e recolher materiais para a extração, amplificação e sequenciamento de DNA. Análises filogenéticas bayesianas e de máxima verossimilhança foram conduzidas a partir de sequências do ITS (nuclear) e do trnL-trnF e petA-psbJ (plastidiais) de 13 das 17 espécies atualmente aceitas, o que corroborou o monofiletismo da seção. Entre as espécies de O. sect. Holophyllum, dez são pela primeira vez descritas em nível específico: O. adpressipila Fiaschi & Bilk (baseada em O. kuhlmannii Lourteig var. adpressipila Lourteig), O. capixaba Fiaschi & Bilk, O. cornicarpa Fiaschi, O. inopinata Fiaschi & Bilk, O. itamarajuensis Fiaschi & Bilk (baseada em O. alata Mart. ex Zucc. var. hirta Lourteig), O. leonii Fiaschi & Bilk, O. occulta Fiaschi & Bilk, O. retrorsa Fiaschi & Bilk, O. sciophila Fiaschi & Bilk e O. septentrionalis Fiaschi & Bilk. Lectótipos são escolhidos para nove nomes e um epítipo para O. impatiens Vell. Uma chave de identificação para todas as espécies é fornecida, bem como descrições, ilustrações, mapas de distribuição geográfica e análises preliminares do status de conservação segundo as normas da IUCN.

We describe three unusual new species of Plukenetia sect. Madagascarienses from eastern Madagascar based on morphology, pollen, and molecular data. Plukenetia analameranensis is unusual in the genus and section for its flat androecium of sessile anthers on a flat receptacle and is most similar to P. ankaranensis sharing obovoid stylar columns. Plukenetia antilahimenae and P. randrianaivoi are distinct in sect. Madagascarienses and among palaeotropical species for their elliptic or obovate-elliptic, pinnately veined leaf blades. They differ primarily in indumentum characters, including stems and inflorescence axes pubescent versus glabrous, and stipule size. Pollen of the new species (unknown in P. randrianaivoi) have reticulate or finely reticulate exines, while that of P. ankaranensis has a rugulate exine; this pollen morphology contrasts with that of all other palaeotropical species, which have foveolate exines. Phylogenetic analysis of nuclear ribosomal ETS and ITS data show that P. randrianaivoi is firmly embedded in the sect. Madagascarienses clade and sister to P. ankaranensis (the other two new species could not be sequenced). Based on these molecular and pollen results, together with floral characters (most importantly completely connate styles), we suggest that the three new species and P. ankaranensis form a subclade, sister to the other two Malagasy species, P. decidua and P. madagascariensis. With the description of these three new species, sect. Madagascarienses (6 spp.) becomes substantially more diverse morphologically. This species radiation in Madagascar resulted in the independent evolution of several leaf and pollen characters that previously were thought to distinguish the two major clades of Plukenetia, specifically pinnately veined leaf blades and reticulate pollen that look remarkably similar to the leaves and pollen of the neotropical pinnately veined clade. An emended description of section Madagascarienses, a key to the species of sect. Madagascarienses, and an updated key to the sections of Plukenetia are provided.

Two recent fieldwork expeditions to Peru and Ecuador resulted in the finding of two Carex species (C. hypsipedos and C. sanctae-marthae) previously known from a single collection each, and of uncertain morphological and systematic affinities. We performed phylogenetic analyses using barcode molecular markers and a detailed morphological comparison among the new specimens and the original collections. A BLAST search was used to obtain the preliminary infrageneric affinities of problematic samples. Phylogenetic results confirmed the adscription of these species to two sectional Carex groups: Carex sect. Racemosae (subg. Carex) for C. hypsipedos and Carex sect. Junciformes (subg. Psyllophorae) for C. sanctae-marthae. Morphological revision revealed unique traits in C. hypsipedos, especially geocarpy, here strikingly reported for the first time for the genus Carex. On the other hand, the careful comparison of the new materials of C. sanctae-marthae revealed unequivocal affinities with the type, confirming its identity as this species. Our work illustrated that for the understanding of poorly known groups, such as these two Neotropical Carex, integrative approaches combining basic biosystematics tools are still very necessary: field and herbaria surveys and DNA barcode.

A new vittarioid fern species, Haplopteris palustris, is here described from the swamp forests in western Malesia based on both morphological and molecular phylogenetic evidence. This species is unique among all recognized congeners with its strongly raised midrib on the adaxial lamina. Through phylogenetic analysis, it is resolved as the sister group of H. sessilifrons, a species usually found in lowland mixed dipterocarp forests. Additionally, we provide chromosome counts for this new species. Our finding underscores the significance of Southeastern Asian swamp forests, emphasizing the need for conservation endeavors and research to ensure the protection of this invaluable ecosystem.

Two new species of Columnea are described from the Andes of Ecuador and Peru. Columnea machupicchuensis J.L.Clark & J.F.Sm. is a subwoody subshrub with tubular purple flowers and is endemic to the forests surrounding the Machu Picchu Inca citadel in the Eastern Cordillera of southern Peru. Columnea flavostriata J.L.Clark is a subwoody subshrub with tubular yellow flowers with purple striations from southern Ecuador. A broad circumscription was initially published that included Columnea lophophora Mansf. and the two newly described species here. The updated circumscription of three species from what was previously considered one species is based on the first collection of Columnea lophophora since the early 20th century, helping to resolve the circumscription and taxonomic boundaries of collections previously considered conspecific. Morphological characters and molecular phylogenetic analyses based on nrDNA ITS are presented that strongly support the circumscription of these three taxa as separate species. Based on IUCN guidelines, a preliminary conservation status is assigned as Endangered (EN) for Columnea flavostriata, Vulnerable (VU) for Columnea machupicchuensis, and Vulnerable (VU) for Columnea lophophora.

Cabari Gregório & D.B.O.S.Cardoso (Leguminosae, Papilionoideae) is a recently described neotropical genus of trees, with species predominantly distributed in the Amazon basin. After robust evidence from a recent phylogenetic analysis of nuclear and plastid DNA sequence data, the genus was segregated from Clathrotropis (Benth.) Harms. Cabari is a genus of large trees with imparipinnately compound leaves and opposite leaflets, inflorescences terminal or less often axillary, woody pods with elastically dehiscent valves, and large seeds. In this taxonomic revision, the genus comprises three species: C. brachypetala, C. brunnea, and C. macrocarpa. We provide morphological descriptions and taxonomic comments for all species, as well as an identification key, three new synonyms, color plates, line drawings, and maps of geographic distribution.

Cabari Gregório & D.B.O.S.Cardoso (Leguminosae, Papilionoideae) é um gênero de árvores neotropicais recentemente descrito, com espécies predominantemente distribuídas na bacia amazônica. Após evidências robustas de uma análise filogenética recente de dados de sequências de DNA nuclear e plastidial, o gênero foi segregado de Clathrotropis (Benth.) Harms. Cabari é um gênero de árvores grandes com folhas compostas imparipinadas e folíolos opostos, inflorescências terminais ou menos frequentemente axilares, legumes lenhosos com válvulas elasticamente deiscentes e sementes grandes. Nesta revisão taxonômica, o gênero compreende três espécies: C. brachypetala, C. brunnea e C. macrocarpa. Nós fornecemos descrições morfológicas e comentários taxonômicos para todas as espécies, bem como uma chave de identificação, três novos sinônimos, pranchas com imagens, ilustrações e mapas de distribuição geográfica.