Sphaerocionium is the largest subgenus of Hymenophyllum and occurs mainly in tropical forests of the Neotropical Region. Species of Hymenophyllum occurring in Brazil are poorly known due to difficulties in species delimitation and the absence of detailed studies. The aim of the present study was to present a synopsis of Hymenophyllum subg. Sphaerocionium in the Atlantic Forest domain, based on molecular and morphological data. Field and herbarium specimens were morphologically analyzed by stereomicroscopy, optical microscopy, and scanning electron microscopy. Phylogenetic relationships were evaluated by sequence comparison of the plastidial regions trnG-R and rps4-trnS. Morphological and phylogenetic evidence led to the recognition of 14 taxa throughout the Atlantic Forest, five of which are endemic. The taxonomy and nomenclature of Hymenophyllum in Brazil are revised and 19 new lectotypifications are proposed. The conservation status and geographical distributions of all species are updated and a dichotomous key is provided.

A new species of Annonaceae endemic to Mexico, namely Desmopsis duran, is described and illustrated. This new species is placed within the Desmopsis-Stenanona clade and is clearly different from any other species of Desmopsis by the combination of elliptic to narrowly elliptic leaves, terminal and branch-like inflorescences, and long pedicellate flowers with six or eight petals. Its morphology and phylogenetic relationships are discussed.

A new species of Macrotorus (Monimiaceae) from the Brazilian Atlantic rainforest is here described and illustrated: Macrotorus genuflexus. This species, restricted to the Poço das Antas Biological Reserve (situated in the central region of Rio de Janeiro state, Brazil), is the second in the genus Macrotorus. The new species description is based on morphological and cytogenetic (karyotype and genome size) comparative analyses. We also report a new record of Macrotorus utriculatus for the state of Bahia, confirming a potential distribution modelling prediction, and provide comments for the conservation of both species.

A new species, Aa tenebrosa, from the Yungas Montane Grasslands is described, illustrated, and compared to similar species. Descriptions, brief taxonomic notes, and data on the ecology of Aa species from the Southern Central Andes (Argentina) are provided.

Species complexes present considerable problems for a working taxonomy due to the presence of intraspecific variation, hybridization, polyploidy, and phenotypic plasticity. Understanding evolutionary patterns using molecular markers can allow for a more thorough assessment of evolutionary lineages than traditional morphological markers. In this study, we evaluated genetic diversity and phylogenetic patterns among taxa of the Platanthera hyperborea (Orchidaceae) complex, which includes diploid (Platanthera aquilonis) and polyploid (Platanthera hyperborea, P. huronensis, and P. convallariifolia) taxa spanning North America, Greenland, Iceland, and Asia. We found that three floral morphological characters overlap among the polyploid taxa, but the diploid species has smaller flowers. DNA sequence variation in a plastid (rpL16 intron) and a nuclear (ITS) marker indicated that at least three diploid species have contributed to the genomes of the polyploid taxa, suggesting all are of allopolyploid origin. Platanthera convallariifolia is most like P. dilatata and P. stricta, whereas P. huronensis and P. hyperborea appear to have originated from crosses of P. dilatata and P. aquilonis. Platanthera huronensis, which is found across North America, has multiple origins and reciprocal maternal parentage from the diploid species. By contrast, P. hyperborea, restricted to Greenland and Iceland, appears to have originated from a small founding population of hybrids in which P. dilatata was the maternal parent. Geographic structure was found among polyploid forms in North America. The area of Manitoba, Canada appears to be a contact zone among geographically diverse forms from eastern and western North America. Given the geographic and genetic variation found, we recommend continued recognition of four green-flowered species within this complex, but caution that there may be additional cryptic taxa within North America.

Vriesea is one of the genera of Bromeliaceae with the highest morphological diversity, including species of difficult recognition, many of them forming complexes, such as the Vriesea oligantha alliance. Morphological and anatomical comparative studies of vegetative and reproductive organs proved to be useful to solve such species complexes, besides indicating adaptive radiation. We analyzed comparatively the anatomy of roots, leaves, peduncles, and peduncle bracts of different populations found in rocky fields of Minas Gerais and Bahia, Brazil, with a taxonomic goal. In all the individuals studied the roots are composed of a velamen, a heterogeneous cortex, and a polyarch vascular cylinder, features that are common in the family. The leaves are covered by peltate trichomes and exhibit a hypodermis on both sides of the blade and a chlorenchyma composed of arm cells forming air lacunae between the collateral vascular bundles. The presence of subepidermal fiber strands in the leaves differentiates the populations of Minas Gerais from those of Bahia. The peduncle has an atactostele with compactly arranged cells in the cortex and pith. The peduncle bracts exhibit a greater number of peltate trichomes on the abaxial surface and secretory channels occur in the mesophyll. A cluster analysis (UPGMA) based on leaf morphology and tank channel diameter generated a dendrogram with four main clusters, which correspond to V. lancifolia, V. oligantha, and V. pseudoligantha, plus another taxon. Intraspecific variations in the color and margin shape of leaves and peduncle bracts are interpreted as adaptive responses to environmental factors, mainly luminosity.

We describe and illustrate Paepalanthus fabianeae, a new species of Eriocaulaceae from the central portion of the Espinhaço Range in Minas Gerais, Brazil. Previous phylogenetic evidence based on analyses of nuclear (ITS and ETS) and plastid (trnL-trnF and psba-trnH) sequences revealed P. fabianeae as belonging to a strongly supported and morphologically coherent clade containing five other species, all of them microendemic, restricted to the Espinhaço range. Due to the infrageneric classification of Paepalanthus being highly artificial, we preferred not assigning P. fabianeae to any infrageneric group. Paepalanthus fabianeae is known from two populations growing in campos rupestres (highland rocky fields) in the meridional Espinhaço Range. The species is characterized by pseudodichotomously branched stems, small, linear, recurved, and reflexed leaves, urceolate capitula, and bifid stigmas. Illustrations, photos, the phylogenetic position, and a detailed description, as well as comments on habitat, morphology, and affinities with similar species are provided. The restricted area of occurrence allied with threats to the quality of the habitat, mainly due to quartzite mining, justifies the preliminary classification of the new species in the Critically Endangered (CR) category using the guidelines and criteria of the IUCN Red List.

Flora endemic to the cold habitats of the Northern Hemisphere provide important models for investigating diversification and disjunctions, given both the intense climatic fluctuations of these areas in the recent past and the fascinating biogeographic patterns of today's Arctic-alpine plant communities. Micranthes Haw. (Saxifragaceae), a clade of small-flowered herbaceous flowering plants comprising ∼80 species, is an ideal group for investigating the evolution and diversification of plants in montane and Arctic ecosystems. Micranthes has proven to be a particularly challenging clade to unravel taxonomically due in part to rampant auto- and allopolyploidy, hybridization, and cryptic speciation. With the goal of providing an updated conspectus for this group, we build upon a recent large phylogenomic analysis to help elucidate the evolution of Micranthes. Here, we present new downstream analyses including diversification analyses, biogeographical reconstructions, and a comparison of methods for dating phylogenomic data sets. To complement these new analyses, we also synthesize chromosomal variation, new observations regarding morphology and species identification, comprehensive field studies, and an extensive review of the literature for Saxifragaceae and Micranthes. A new perspective on the systematics and taxonomy of Micranthes is provided.

The recently resurrected monotypic genus Monrosia (Polygalaceae) is endemic to the Argentinian provinces of Catamarca to San Juan in the southern Andes. We here describe and illustrate Monrosia sanjuanensis, a new species endemic to the province of San Juan and the second species of the genus, and revise the genus. Monrosia and its two species are described and analysed in a phylogenetic context, using nuclear and chloroplast DNA sequences. A distribution map, illustration, photos of the morphological structures of the two species, and taxonomic key are provided. We designate a lectotype for the name M. pterolopha.

While studying Urticaceae from the southern region of Brazil, we found two new species, Pilea tenebrosa and Pilea acanthoides, which were collected in the states of Santa Catarina and Paraná, respectively. These species are here described, illustrated, and compared to morphologically similar species. An identification key to the species of Pilea in southern Brazil also is provided.

Turnera macrosperma, a new species from the Brazilian Cerrado, is described and illustrated. The new species belongs to the series Turnera and can be characterized by the white petals with dark blue/violet basal spot and large seeds with papillose aril. SEM images, distribution map, and comments on taxonomy and morphology are presented.

We present a new species, Turnera fasciculifolia, from the Jalapão region, the largest continuous protected area of Cerrado in Tocantins State, in central Brazil. The new species belongs to Turnera series Leiocarpae, and it can be recognized by the linear ericoid leaves with revolute margin, generally without extrafloral nectaries, and the basal leaves of the young axillary branches gathered in fascicles. We provide a description, illustrations, a distribution map, and a comparison with T. genistoides and T. revoluta, which also have ericoid leaves.

A new species (Tragia hoffmanniae) found only in the Atlantic Forest in the state of Bahia (northeastern Brazil) is presented here, with descriptions of its morphology and pollen grains; illustrations, maps, and geographical and morphological comments are also provided. The species differs from other Tragia sect. Tragia taxa in having leaves with an elliptic to lanceolate blade, caudate apex, and entire margin. A comparative table is provided to distinguish the new species from other Tragia species in the Atlantic Forest.

We examine investment in male function in the context of geography and floral morphology in the plant ring species Euphorbia tithymaloides, which colonized the Caribbean from Mexico/Guatemala along two fronts that roughly correspond to the Greater and the Lesser Antilles and that meet in the vicinity of the Anegada Passage. Our results on investment in pollen relative to ovule production are consistent with E. tithymaloides relying on pollinators for reproduction across its range in the Caribbean. We document a geographic pattern of reduction in anther number and pollen:ovule ratios in populations of E. tithymaloides towards the Anegada Passage, which is consistent with a possible geographic transition towards a mixed breeding system where selfing has increased importance in this area where its two expansion fronts meet. The reduction in pollen production is correlated with inflorescence morphology, which converges to relatively shorter cyathia towards the Anegada Passage along both fronts. We discuss alternative scenarios and potential drivers of the patterns we document.

The recent rediscovery of Jatropha riojae, which was considered as probably extinct, led to a taxonomic re-evaluation of the species due to its problematic circumscription with respect to morphologically similar species of Jatropha section Loureira subsect. Loureira. Based on our study, J. riojae is accepted, taxonomic clarifications are made, including the designation of a lectotype for the name, a complete description of vegetative and reproductive structures is provided, and the species is illustrated and compared to others with which it has been confused. The geographical distribution of J. riojae is clarified as endemic to the municipality of Acatlán, Puebla, Mexico in the south of the Balsas River Basin. To determine the conservation status of the species, the risk assessment method of the Mexican Red List (NOM 059-SEMARNAT-2010) was applied, indicating that J. riojae should be assigned to the “Endangered” category. A re-evaluation of the species under the IUCN criteria indicated that it should be assigned in the “Critically Endangered” (CR) category.

Medinilla (Melastomataceae) is a large paleotropical genus with the Philippines as one of its greatest centers of diversity. However, exceptionally few species are recorded from Palawan. Notes on the Medinilla species of Palawan and an identification key are provided. Ten species are recorded, double the previous number. Two species are newly described: Medinilla simplicymosa and Medinilla ultramaficola. The Medinilla of Palawan remain poorly understood.

Chromosome counts from 23 populations of 16 species of Paullinia (Paullinieae, Sapindaceae) from South America are given. These include first counts for ten species in six of the thirteen sections of this genus. Counts of 2n = 24 for P. cristata, P. revoluta, P. thalictrifolia, P. trigonia, P. uloptera, P. rhomboidea; 2n = 48 for P. seminuda and P. sp.; and two cytotypes of 2n = 48 and 2n = 96 for P. carpopoda and P. rubiginosa; and ca. 2n = 216 for P. cupana var. sorbilis. The chromosome number 2n = 24 appears to be conserved for this genus, however, in this contribution polyploid series are cited for the first time for some native species. These results were interpreted in a phylogenetic context.

The genus Cardiospermum comprises eight species distributed in the American continent, from central-eastern United States of America to central Argentina, Uruguay, and Chile; C. corindum, C. grandiflorum, and C. halicacabum are distributed worldwide. How these species spread to the African continent from the Americas and from Africa to the rest of the world remains to be understood. Two hypotheses were tested in this study: the species would have colonized the African continent either naturally, through extreme long-distance dispersal, or via human activities. Our work considers the niche conservatism principle, which states that a species tends to retain aspects of its fundamental niche over space and time; however, a deviation (i.e. niche shift) may be detected, indicating that the ecological and evolutionary traits of the species change in response to environmental modifications. We compared the niche of each of the three species based on their known occurrences, both in the Americas and in the rest of the world, and on climatic variables. We performed an environmental niche modelling analysis for three periods: Holocene, Last Glacial Maximum, and the present. In addition, a Principal Components Analysis of climatic variables associated with known occurrences was performed through the COUE scheme. Our results suggest an early migration of C. corindum and C. halicacabum from the Americas to Africa; therefore, these two species would be native to these ranges, as proposed in previous studies. In addition, a recent introduction event of C. grandiflorum to Africa, and from Africa to India, Asia, and Oceania, was detected, which confirms the invasive status of this species outside the Americas.

The karst area in South China is notable for its fragile vegetation and unique flora with many narrow endemic species, and is one of the most threatened biodiversity hotspots in the world. However, the biodiversity of acid soil areas scattered in the karst area have previously been underestimated. With a recent increase of new discoveries of plants and animals, the conservation of biodiversity in these acid soil areas has become urgent. This study deals with a new species, Impatiens longlinensis. The new species is similar to I. yui and I. lasiophyton in having pubescence, two lateral sepals, funnelform lower sepal, and linear capsule. But it can be distinguished by having orbicular to obovate dorsal sepals and oblong to elliptic lower and upper lobes of lateral united petals. Moreover, molecular data and micro-morphological evidence also support that the species is new to science. The new species is only known from a valley near the summit of Mt. Jinzhongshan within an area of less than 5 km². Based on the Red List categories and criteria developed by the International Union for Conservation of Nature, and the threat posed by exploitation for tourism development, we categorize it as Critically Endangered (CR).

Kalmia buxifolia (sand-myrtle, Ericaceae) is disjunctly distributed across the high-elevation rock outcrops of the southern Appalachians, upper monadnocks and pine savannas of the Carolina Piedmont and Coastal Plain, and the New Jersey Pine Barrens. Here, we sampled plants from each region and reconstructed the phylogeographic history of K. buxifolia to test a rock-outcrop Pleistocene refugium hypothesis, estimate the potential direction(s) and timing of migration, and date divergence from its alpine sister species, K. procumbens. We also assess whether isolation in these different environments has led to variation in intrinsic water-use efficiency. Dating analysis challenges the current hypothesis that rock-outcrop species are relics of Pleistocene refugia (< 18,000 ybp), placing the divergence of K. buxifolia and K. procumbens much earlier, in the late-Miocene (9.40 Ma). Chloroplast haplotype analysis indicates four potential refugial sites, with the most ancient on Mount LeConte in the Great Smoky Mountains, and point to an Appalachian corridor as the likely Pine Barrens colonization route. The sister species divergence time and population level divergences within K. buxifolia generally coincide with major climatic shifts from the late-Miocene to mid-Pleistocene. Results from carbon isotope discrimination indicate that plant water-use varies geographically within K. buxifolia, as does leaf morphology, although it is unclear whether this variation is due to genetic adaptation or phenotypic plasticity. These patterns of phylogenetic divergence and resulting ecophysiological diversity within K. buxifolia are significant for clarifying long-held questions about the biogeographic history and trait differentiation within this species. Further, our results suggest that high-elevation rock outcrop communities may have been inhabitated by northern-affinity species for much longer than previously assumed, and that subsequent population disjunction and isolation may have resulted in ecophysiological differentiation in these communities.

Antiphytum charruasorum, a new endemic species from western Uruguay, is described. This is the only South American species in the genus with white corolla and an infra-medial cicatrix on the ventral face of the eremocarp, both features shared with the North American species of Antiphytum, in sharp contrast with the blue corolla and the basal cicatrix at the end of a stipe-like prolongation that characterizes all South American species in the genus. Antiphytum charruasorum increases the diversity of the genus in South America, as well as the endemism and distribution range into Uruguay. Moreover, this new species adds novel features in Antiphytum such as the irregularly dichasial inflorescences, the hirsute faucal appendages, the eremocarps with a tissue plug from the gynobase, and the habitat where the species has been reported.

Daustinia montana (Convolvulaceae) is the only species of the genus, and is notable for its wide leaf variability. To understand whether this plasticity is correlated with the distribution of the species, linear morphometric and leaf contour analyses were performed. Specimens from herbaria were photographed, and pre-established linear measurements were made. A multivariate analysis was then performed to test the strength of associations among morphological characteristics, climatic variables, and distribution of the species. Elliptic Fourier analysis based on 20 harmonics was used to generate shape descriptors, resulting in nine main components. With elliptic Fourier descriptors, a grouping tree was created that suggests the existence of six morphotypes in D. montana. Moreover, clustering analysis revealed two large groups distinguished mainly by leaf width. The present findings indicate that the morphotypes are strongly related to latitude and that other characteristics such as the type of indumentum are related to climatic variables.

Solanum confertiflorum (Solanaceae), a new species for the Cyphomandra clade, is described and illustrated. The species is endemic to Bahia state, in Brazil, restricted to few localities, inhabiting seasonal forests and outcrops in the Caatinga biome. It is morphologically related to S. luridifuscescens, sharing the papillose anthers without swollen connectives, but distinguished by the forked cymes with flowers congested at the apex, swollen calyx with shorter lobes, as well as shorter, sessile stamens. The morphology, geographic distribution, ecology, and conservation status are discussed and a key for the Brazilian species without swollen connectives belonging to the Cyphomandra clade is presented.

Baccharis funkiae, a new species endemic to Uruguay, is described and illustrated here. We also provide field work pictures, etymology, distribution and habitat, and preliminary conservation status information. Comments on how to differentiate it from the morphologically similar B. subopposita, highlighting differences setting the new species apart are discussed. Additionally, a key to the identification of the Uruguayan species belonging to Baccharis subgen. Baccharis sect. Cylindricae is presented.