Previous phylogenetic analysis of ITS nrDNA sequence data for Arctotidinae species resolved a strongly supported clade containing all but one of the showy annual Arctotis species (informally designated the Arctotis Annual Clade). In the present study, phylogenetic relationships in the Arctotis Annual Clade were investigated by Bayesian inference and maximum parsimony analyses of cpDNA (trnT-trnL-trnF and trnH-psbA) and nrDNA (ITS) sequence data. The cpDNA and nrDNA phylogenies were notably incongruent. Arctotis venusta and a putative unnamed species (A. ‘sp. B’) were strongly supported as monophyletic by both data sets. The monophyly of A. leiocarpa was strongly supported by the ITS data set, whereas the remaining accessions formed a poorly resolved complex (the ‘A. fastuosa complex’). Within the A. fastuosa complex, A. hirsuta was monophyletic with strong support in the ITS phylogeny. A statistical parsimony-derived cpDNA haplotype network resolved five broad groups of haplotypes and showed no consistent geographical structure, but species-specific haplotype lineages for A. venusta and A. sp. B were resolved. Arctotis fastuosa accessions were distributed among four haplotype groups. Incongruence between the data sets and poor resolution within the A. fastuosa complex may reflect reticulate evolution, ancestral polymorphism, and incomplete lineage sorting, in tandem with the low information content of the data sets. The greatest phenotypic diversification in the clade is in cypsela morphology. Comparison of cypsela morphology with the phylogenies suggests a general trend for reduction in the sizes of the cypsela, abaxial wings, pappus scales, and loss of pubescence during diversification. A revised taxonomy, integrating currently available evidence, accompanied by full descriptive accounts and a key to the taxa are presented. Eight species are recognized, including the nomenclatural novelties Arctotis chrysantha (sp. nov.) and Arctotis namibiensis (sp. nov.). The names Arctotis karasmontana, Venidium fugax, and Venidium macrocephalum are lectotypified.

Spiranthera (Rutaceae, Galipeeae) is a neotropical genus, recognizable mainly by the presence of trifoliate leaves, pentamerous flowers, exappendiculate filaments, spirally revolute anthers lacking a basal appendage, a campanulate disk, and anelongated gynophore. Species in this genus are mostly sciophilous treelets from South American rainforests, except for Spiranthera odoratissima, the most widespread species, which is a shrub inhabiting savannic formations and showing the widest morphological variation within the genus. In this taxonomic revision we present an extensive morphological analysis of the genus based on data from field work and from herbaria, an identification key, and descriptions and illustrations of the six species here recognized, including a new one from Iquitos, Peru. Also, we present updated information on the geographic distribution of the species, their habitats, and their morphological variability.

Diastatea (Campanulaceae-Lobelioideae) is a genus of small, herbaceous annuals found mostly in Mexico. Differences in the number of recognized species in the historical treatments, and the lack of a phylogeny, suggested that a revision of the genus was necessary. Species boundaries and species level relationships were tested based on a sampling of nearly 50 individuals. Sequences of the chloroplast spacer regions, atpB-rbcL and ndhF-rpl32, as well as the ITS, were generated and then analyzed using maximum likelihood and Bayesian inference methods. The analyses of the separate datasets produced congruent topologies. Two strongly supported clades of Diastatea are newly recognized as subgenera in the taxonomic treatment. Diastatea Scheidw. subg. Diastatea and Diastatea subg. Angustifolia E.P.Johnson & T.J.Ayers can be distinguished morphologically by leaf shape and pubescence, hypanthium shape, and the presence or absence of a gibbous projection on the ventral side of the corolla. A morphological treatment of the genus corroborated by the molecular analysis revealed one new species, Diastatea aptera E.P.Johnson & T.J.Ayers, one new subspecies, Diastatea tenera subsp. durangensis E.P.Johnson & T.J.Ayers, and elevated an existing subspecies, Diastatea ciliata (McVaugh) E.P.Johnson & T.J.Ayers, to specific rank.

Two new species of lycophytes, Selaginella obovata and S. zhangii, were discovered in southeastern Yunnan, China. Selaginella obovata is characterized by the prostrate habit and relatively small size of plant, obovate median leaves, and short, dorsiventral strobili, and is not apparently similar to any known species. Phylogenetic analyses of plastid sequences (rbcL, atpI, psbA) indicated that S. obovata is closely allied to S. bisulcata, which is also supported by spore morphology, and that these two taxa together with S. pennata constitute a well-supported monophyletic group. Selaginella zhangii is comparable to S. rolandi-principis in their broad stems and shape and arrangement of vegetative leaves; but the former differs from the latter in its prostrate habit and dorsiventral strobili. The results of phylogenetic analyses indicated that S. zhangii is allied to S. heterostachys in the S. heterostachys–S. ciliaris clade, while S. rolandi-principis is distantly placed in the S. doederleinii–S. involvens clade. Finally, we provide comprehensive descriptions, photographs of living plants, line drawings, and scanning electron micrographs of spores to facilitate their recognition.

A taxonomic treatment is herein provided for the six primarily Neotropical species of Vigna subg. Lasiospron. This subgenus is distinguished, in part, by its close relationship with Old World Vigna species, but rather than having an Old World Vigna floral asymmetry where distal floral parts can have a right-hand curvature (from a face-view perspective), distal parts of Vigna subg. Lasiospron flowers, like those of American Phaseolinae, curve to the left. Our proposed taxonomy reflects published phylogenetic analyses that resolve the Vigna subg. Lasiospron species in a subclade of the primarily Old World clade of species of Vigna sensu stricto. Vigna subg. Lasiospron is therefore distinctive in having a primarily neotropical distribution. Three of the six Vigna subg. Lasiospron species have an amphi-Atlantic distribution, which we suggest was achieved naturally by the ability of these species to disperse and colonize coastal habitats. Nomenclatural and taxonomic synonyms are reported, along with species descriptions and the biogeographical, genetic, and morphological evidence that argues for each of the six Vigna subg. Lasiospron species fitting a unified species concept.

New entities in the allopolyploid Dilatata complex of Paspalum are formally described and illustrated. Three sexual tetraploids formerly subsumed under Paspalum dilatatum are recognized as discrete taxonomic entities: P. plurinerve and P. vacarianum are described as new species, and P. dilatatum subsp. flavescens is upgraded to species rank as P. flavescens. Both P. vacarianum and P. plurinerve are distributed in the Brazilian southern Plateau (Planalto Meridional), in the states of Rio Grande do Sul and Santa Catarina, the first one in the eastern region and the second one in the western region including adjacent areas of NE Argentina. Paspalum flavescens is distributed in southeastern Uruguay and the provinces of Buenos Aires and Córdoba (Argentina). The apomictic allohexaploid P. torrense, distributed along the coastal areas of the Brazilian states of Rio Grande do Sul, Santa Catarina, and Paraná, and adjacent regions along the edge of the southern Plateau, also deserves specific status, whereas two further hexaploid biotypes are differentiated from the pentaploid P. dilatatum var. dilatatum and described as Paspalum dilatatum var. chiru and P. dilatatum var. uruguaianense. Paspalum dilatatum var. chiru is restricted to a small area around the locality of Molles Grande, in the department of Paysandú, Uruguay; whereas P. dilatatum var. uruguaianense is distributed in the SW of Rio Grande do Sul, Brazil, and northern Uruguay. The Dilatata group of Paspalum is thus comprised of 8 species and 3 varieties, which are summarized here and for which an identification key is provided.

Understanding species level relationships is a central goal in systematic botany; however, complexes of closely related and morphologically similar species often pose considerable challenges to that goal. The North American west is home to many notable genera that notoriously have difficult species complexes (e.g. Astragalus, Eriogonum, Penstemon). Mentzelia section Bartonia (Loasaceae), another example of a group with difficult species complexes, is a recently evolved and diverse clade that occurs across the North American west. Phylogenetic studies have resolved many relationships across Mentzelia, but the relationships within a species complex of perennial, subshrub species that occurs in the Mojave Desert, Great Basin, and Colorado Plateau remains elusive. This arid-adapted clade, which is referred to as the Mojave clade, has significant conservation implications due to three narrowly endemic species: Mentzelia polita and Mentzelia tiehmii are state listed, and Mentzelia leucophylla is federally listed. Species relationships within the Mojave clade are not fully understood. Populations of Mentzelia oreophila from California and Nevada, for example, are not monophyletic. We generated restriction site associated DNA sequence data (RADSeq) to address evolutionary relationships in the Mojave clade. Our results corroborated previous studies in continued recognition of Mentzelia polita, Mentzelia leucophylla, and Mentzelia tiehmii; however, Mentzelia oreophila was recovered in three clades that includes a California clade, a Nevada clade, and one with Mentzelia puberula. Incomplete lineage sorting and hybridization might have generated conflicting phylogenetic signal between Mentzelia oreophila and Mentzelia puberula. Increasing population level sampling will aid in species delimitation and further help to understand how gene flow and/or hybridization is influencing population level dynamics in the Mojave Desert.

Two new species of Dyschoriste (Acanthaceae), endemic to northeastern Brazil, are described: D. eulinae and D. vinacea. For each species we also provide a diagnosis, illustrations, taxonomic comments, preliminary conservation assessments, palynological data, distribution map, and photographs. A key to the species of Dyschoriste occurring in northeastern Brazil is presented.

Two new species of Eriocaulon (Eriocaulaceae) from the Brazilian Cerrado are described and illustrated. Eriocaulon benedictum, found in the Tocantins River Basin and Plate River Basin has a vegetative morphology similar to Eriocaulon aquatile and E. modestum due to the submerged life form with submerged leaves and long scapes surpassing the water column, but differs from both by the presence of a submerged stem with spiral leaves (vs. a rhizome with rosulate leaves), obtrullate floral bracts (vs. oblong floral bracts in E. aquatile or obovate in E. modestum), and band shaped projections on the seeds (vs. post shaped projections on E. modestum or projections absent in E. aquatile). Eriocaulon naviculum, found in the Araguaia River Basin, an emergent species, has a floral morphology similar to E. altogibbosum and E. gibbosum due to the presence of gibbous sepals in the pistillate flowers, but differs from both by the grey trichomes on the leaf sheath (vs. translucent trichomes in the latter species), slightly sinuous scapes (vs. straight scapes in the latter species), membranous, gibbous swelling in the sepals of the pistillate flowers (vs. incrassate gibbous swelling in the latter species), and seeds without projections with a rough lumen (vs. seeds without projections with a smooth lumen in E. gibbosum or seeds with band-like projections in E. altogibbosum). Detailed descriptions, including anatomical and seed data, illustrations, and maps of occurrence are presented for the new species, as are data on the ecology, geographic distribution, and risk assessments. An updated key for Eriocaulon species from the Tocantins-Araguaia River Basin is also provided.

Justicieae is one of the largest tribes of Acanthaceae, composed of 2000 species distributed in 100 genera, with highest diversity in the neotropical region. Palynological studies containing several representatives of the tribe are rare, specially species from Northeastern Brazil. The present study aims to differentiate species and evaluate palynological characters in the light of a phylogenetic hypothesis of Justicieae. Eighteen species belonging to six genera were analyzed. Pollen grains were acetolyzed, measured and photographed under light microscopy (LM) and scanning electron microscopy (SEM). Pollen grains are medium to very large in size, isopolar, planaperturate, subprolate, prolate to prolate spheroidal, and two-colporate to three-colporate, or with six pseudocolpi. The exine ornamentation is microreticulate to reticulate with areolae between the apertures in most species. Some species present a cavea in the mesocolpium. The pollen morphology of Justicia chamaedryoides, J. congrua, J. glaziovii, J. thunbergioides, J. sphaerosperma, Pseuderanthemum congestum, and P. modestum are hereby described for the first time. A new combination is also proposed, Thyrsacanthus angustissimus.

We report Eryngium absconditum, a new species from Cordillera de Amambay, an area that belongs to the biodiversity hotspot of the Cerrado in Paraguay. The species was collected more than a century ago, but the collections remained unnoticed and misidentified until now. We describe, illustrate, and provide information on the geographical distribution and habitat of the new species. We also analyze and illustrate the morphological characteristics that differentiate it from Eryngium rojasii and E. paraguariense, the most similar species to the new. This study highlights the importance of Amambay as an area rich in endemic plant species and the need for continued taxonomic studies and the establishment of regional conservation policies for this region with its biodiversity under threat.

The genus Hechtia includes 91 species (with those described herein), 88 of them present in Mexico, and the entire genus is endemic to the region termed Megaméxico 3 by Rzedowski. With 21 species, the Mexican state of Puebla is the second most species rich. As a result of botanical exploration for the project Bromeliaceae of Mexico, we describe here seven new species, all endemic to Puebla: Hechtia anarosae, H. dasylirioides, H. espejoana, H. longissimifolia, H. microcarpa, H. minimiflora, and H. vicesphaeroblasta. The proposed species are compared with morphologically similar taxa (H. caulescens, H. ensifolia, H. flexilifolia, H. fragilis, H. podantha, and H. sphaeroblasta). Morphological descriptions, images, and a map with distributions of the described taxa are included, as well as an identification key and a list of specimens examined of all the species of Hechtia currently known from the state of Puebla.

The subgeneric classification of the neotropical legume genus Zapoteca is revised based on an analysis of the nuclear ETS and ITS, and the plastid trnL-trnF DNA regions. Zapoteca subgenus Ravenia is included in Z. subgenus Zapoteca, Z. quichoi is transferred from Z. subgenus Amazonica to Z. subgenus Zapoteca, Z. sousae is included in Z. subgenus Zapoteca, and the new subgenus Zapoteca subgenus Subamazonica is described to accommodate the species Z. filipes and Z. scutellifera. A key to the subgenera is presented.

The Habenaria repens complex comprises ca. 14 species distributed from the southern United States to northern Argentina. In Brazil, several morphotypes with similar ecological preferences to H. repens s. s. occur, which have made identification at the specific level challenging. In an associated article using molecular phylogenetic, morphometry, and population genetic analyses, we showed that the H. repens complex is polyphyletic and subdivided into three main distantly related clades. Four of the studied morphotypes are phylogenetically distant from H. repens s. s. and morphologically distinct from all other taxa in the complex. They are described here as H. bryophila, H. hygrophila, H. subrepens, and H. compluviosa. Similarly to H. repens s. s., these newly proposed species show preferences for aquatic environments, but differ in habitat specificity, phenology, and morphology. The new taxa are restricted to upland, wet grasslands associated with campos rupestres occurring in the Espinhaço Range in the states of Minas Gerais and Bahia, or other mountainous areas of Minas Gerais and Goiás. We provide a diagnosis with detailed morphological characterization for each species, including etymology, distribution, informal conservation assessments, data on habitat and phenology, notes, images, and diagnostic characters to separate them from each other and H. repens s. s.

Two new species of Polygala (Polygalaceae) from the phytogeographic province of La Payunia are reported: Polygala payuniensis, endemic to northern Neuquén and southern Mendoza provinces, Argentina; and Polygala nevadensis, endemic to Sierra del Nevado in Mendoza province, Argentina. The new species are described in detail, illustrated, and their informal conservation status calculated. A distribution map and photos of the dissected structures are provided for both species as well as photos of the living plant and the environment for P. payuniensis. Also, an updated key to the species of Polygala Sect. Clincinia is provided.

We describe two new species of Calibrachoa (Solanaceae) from southern Brazil grasslands. The new species were first detected by molecular data, and later corroborated by morphological traits and field observations. Both species are erect shrubs with showy purple corollas. The main distinctive morphological traits are the marked dark purple ring contrasting with the yellow corolla throat and the lobed stigma in C. atropurpurea, and the long androecium reaching the distal part of the corolla tube and the connivent anthers in C. synanthera. A key for the species with purple flowers from the Rio Grande do Sul Brazilian State, where the species were found, is given.

The genus Paraphlomis (Lamiaceae) consists of approximately 30 species, most of which are restricted to the subtropical area of China. In this study, P. longicalyx Y.P.Chen & C.L.Xiang, a new species from southern China, is described and illustrated. Molecular phylogenetic analyses implemented based on two nuclear ribosomal DNA and four plastid DNA regions showed that P. longicalyx is a distinct lineage from all morphologically similar species within the genus. Morphological examination demonstrated that the new species is most similar to P. javanica and P. foliata, but can be distinguished from these species by its densely hispidulous surfaces, much longer calyces, and pale-yellow corollas with reddish-purple spots on the lower lips.

Euphorbia xiangxiui, a new species of Euphorbiaceae from Eastern China, supported by morphological and molecular evidence, is illustrated and described here. It can be distinguished from its closest relatives by the combination of several characters, including taller stature (up to 1.6 m), leaves of 5–18 × 0.6–3 cm in size, color of primary involucral leaves and cyathophylls changing from pink to rose, fading to green after fruiting, and four to six reniform-rounded concave glands. The molecular phylogenetic analysis, based on combined nuclear ribosomal ITS and plastid ndhF sequences, further supports that E. xiangxiui should be placed in the East Asian Clade of Euphorbia subg. Esula sect. Helioscopia.

As currently circumscribed, the legume genus Enterolobium comprises 11 species in two sections: E. sect. Enterolobium and E. sect. Robrichia, with an overall distribution from Mexico to Argentina and a centre of diversity in Amazonia. In the absence of the characteristic indehiscent fruits, Enterolobium is difficult to distinguish from other genera in the ingoid clade, including Albizia sensu lato, Samanea, and Cathormion. Previous phylogenetic studies which have included Enterolobium have sampled few species of the genus, leaving questions about its monophyly and interspecific relationships. Here we evaluate the circumscription of Enterolobium and its two infrageneric taxa, their phylogenetic placement in the ingoid clade, and interspecific relationships within the two sections of the genus. Our study includes all Enterolobium species, and analyses of nuclear (ITS and ETS) and plastid (trnD-T and trnL-F) molecular regions, and morphology. Bayesian inference, maximum parsimony, and maximum likelihood analyses show that Enterolobium, as presently circumscribed, is not monophyletic. The genus is divided into two well-supported independent clades, corresponding to the two previously recognized sections; one of them is sister to the genus Leucochloron and is here raised to generic rank as the genus Robrichia, with three species, Robrichia glaziovii, Robrichia oldemanii and Robrichia schomburgkii. The genus Enterolobium consequently now comprises eight species and is more closely related to a clade composed of Albizia and Falcataria. This new arrangement is reinforced by morphological synapomorphies recovered by ancestral character state reconstructions. Indumentum type, the number of pinnae pairs per bipinnate leaf and leaflet pairs per pinna, inflorescence type, and fruit shape characterize Robrichia, while the recognition of Enterolobium remains based on fruit traits. We also provide the formal lectotypifications for E. contortisiliquum, E. cyclocarpum, E. gummiferum, E. maximum, E. monjollo, and R. schomburgkii.

The genus Spigelia (Loganiaceae) is a Neotropical genus that includes more than 80 species distributed from the United States to Argentina. Systematic studies of the group have rarely considered the carpological characters, so their taxonomic importance has not been analyzed in detail. The aim of this study is to analyze the morphological characteristics of these organs to provide more information for a better species separation and for a more robust infra-generic classification. We provide a detailed description of Spigelia fruits and seeds of the Mexican species since the country represents one of its main centers of diversification. Fruits and seed samples from 54 individuals across 14 species were measured and photographed to describe each one, maintaining as much detail as possible. With the morphological matrix a DFA, PCA, and a dendrogram using the NJ method was performed. The fruits and seeds of the Mexican Spigelia species proved to be taxonomically useful, allowing the differentiation of four main clusters of species separated by the size of the analyzed structures in the three analyses (DFA, PCA, NJ). The results show the variation in size and shape of the structures analyzed, which shows the taxonomic importance of fruits and seeds of the genus Spigelia. Our work represents an advance in the detailed knowledge of structures, which are rarely considered in the descriptions, and which allows us to have a separation of species. A taxonomic treatment and photographs of the fruits and seeds are also included.

Masdevallia britoi, a new species in Masdevallia sect. Minutae, is described and illustrated from the central Amazon in Brazil. It is similar to M. wendlaniana but differs by shorter sepals that are internally white, shorter oblong petals with a delicate tooth near the middle, shorter lip with deltoid marginal folds near the middle and three-denticulate apex, and shorter ovary. The new species grows in the white-sand forests locally known with the name Campinaranas. We also provide an identification key for the species of Masdevallia from the Brazilian Amazon.