Piper globirhachis, a new species from northwestern Amazon, is described and illustrated. It occurs across the Marañon River Valley from its close relative P. nudilimbum with which it has been confounded for ca. 100 yr. Piper globirhachis differs morphologically from P. nudilimbum in having ovate to long-ovate leaf blades and globose inflorescences, vs. elliptic leaves and elongate inflorescences in P. nudilimbum. These species also differ in geographic distribution and ecological niche. A molecular phylogeny based on 135 ITS sequences (125 from Neotropical Piper species and 5 Asian Piper species) enabled the species boundary test (Poisson-tree-processes, PTP) corroborating that these are distinct species. Furthermore, these two species formed a well-supported clade sister to P. subgenus Oxodium (=Schilleria). This phylogeny highlights the importance of allopatric speciation in Piper and provides evidence for the resurrection of Pleiostachyopiper as a subgenus of Neotropical Piper. An identification key for the subgenera of Neotropical Piper is provided.

Beilschmiedia mengwangensis, a new species of Beilschmiedia (Lauraceae) from Yunnan Province, Southwest China, is here described and illustrated based on morphological and phylogenetic evidence. The new species is morphologically similar and phylogenetically closely related to Beilschmiedia brachythyrsa. However, it can be distinguished from Beilschmiedia brachythyrsa by having larger fruits, longer and thicker fruiting pedicels, larger leaf blades, and more lateral veins. Taxonomic keys for identification are also provided in this study.

Based on the recent phylogenetic study on Ornithocephalus clade, we propose ten new combinations to include the genus Eloyella in Dunstervillea.

The Sierra Madre del Sur (SMS) biogeographic province parallels the Pacific Ocean from the state of Jalisco to Oaxaca and Puebla. The area is very complex tectonically and geologically and harbors the highest number of vascular and endemic plant species in Mexico. Here, we describe Tigridia nana as a new species in this province. Furthermore, during the revision of herbaria and digital collections, we created a database to provide a biogeographical analysis of Tigridieae in the SMS. Morphologically, T. nana pertains to Tigridia subgenus Tigridia. The nectary has secretory trichomes that extend across the inner tepal, the base of the much reduced limb inflexes, and then covers it. Tigridia nana is endemic to Oaxaca coexisting in the SMS with 34 other species of Tigridieae. The group is very diverse in the state of Oaxaca, with the species richness and endemism concentrated in the Oaxacan Highlands district. The pine-oak forest harbors the greatest species richness. Our findings coincide with the species richness and endemicity values of some other plant groups in the SMS.

We examine the Digitaria filiformis complex to determine the proper taxonomic rank and conservation status of each member. The taxonomy of the D. filiformis complex is debated and includes two widespread taxa, D. filiformis var. filiformis and D. filiformis var. villosa; a rare taxon of southern Florida and the West Indies, D. filiformis var. dolichophylla; and a possibly extinct taxon that supposedly is a single-site endemic in New Hampshire, USA, D. filiformis var. laeviglumis. We conducted molecular analyses and morphologic comparisons of the four members of the D. filiformis complex, together with specimens from Venezuela (morphology only) and Mexico purportedly identified as D. filiformis var. laeviglumis. Based on results of phylogenetic analyses of plastid and nuclear ITS sequences and morphologic comparisons, we elevated taxonomic ranks, recognizing four species in the D. filiformis complex, and circumscribe the Mexican species D. glabrifloris (sp. nov.). Digitaria dolichophylla is much rarer than previously recognized, moving from Secure Globally to Imperiled with extinction (G2). After research and field investigations, we changed the global rank of D. laeviglumis from Globally Historical (GH) to Globally Extinct (GX), as there is virtually no likelihood of rediscovery.

Arthrostylidiinae (Poaceae: Bambusoideae), a subtribe of Neotropical woody bamboos with diverse morphology, comprises 200 species classified in 16 genera. Previous studies supported monophyly of the subtribe and recovered four major internal clades, however, some genera were found to be polyphyletic while others, like Aulonemia and Colanthelia, were either undersampled or not included. Aulonemia and Colanthelia are complex both in their taxonomy and morphology, and exhibit overlapping morphological characters. Prior morphological and molecular analyses suggested they share a close relationship, with Colanthelia emerging as monophyletic and either nested within Aulonemia or sister to it, but these studies sampled relatively few species of each genus. The aims of this study were to increase taxon sampling to test the monophyly of Aulonemia and Colanthelia, to investigate the relationships within the Aulonemia + Colanthelia clade, and to revise their classification as appropriate towards a natural classification of the Arthrostylidiinae. We present a multi-locus plastid phylogeny of the Arthrostylidiinae with emphasis on Aulonemia and Colanthelia. We used sequences of seven plastid markers (one coding: ndhF; six non-coding: trnC-rpoB, rps16-trnQ, trnT-trnL, rps16, trnD-trnT, and rpl16) from 67 taxa of Bambusoideae including all genera of Arthrostylidiinae. Phylogenetic trees were inferred using both Bayesian and maximum likelihood methods. Aulonemia was confirmed as polyphyletic and Colanthelia was not supported as monophyletic. The phylogenetic position of Myriocladus within Arthrostylidiinae is resolved for the first time. All species of Colanthelia were recovered within the clade containing most species of Aulonemia. Four species of Aulonemia (A. radiata, A. effusa, A. setosa, and A. setigera) grouped in other clades within the subtribe and these placements combined with morphological evidence support the establishment of three new genera: Quixiume, Stelanemia and Vianaea, to accommodate the four remarkable Aulonemia species. An updated key for the genera of the Arthrostylidiinae is provided, as well as taxonomic treatments for the three new genera, including the description of a new species in Stelanemia.

Until now, phylogenetic relationships for the genus Calliandra section Androcallis (Fabaceae) were unresolved. We reconstructed the phylogeny of the section, including previously sequenced species from Central and South America and unexamined species from Colombia. Here, we generated 80 novel DNA sequences of Calliandra species from Colombia for the nuclear internal transcribed spacer (ITS) and the chloroplast trnL and trnL-F intergenic spacer. By incorporating a broader taxonomic sampling, the relationships among main clades in C. sect. Androcallis were clarified, providing a systematics framework in which to test evolutionary hypotheses. Phylogenetic analysis recovered four well-supported clades within C. sect. Androcallis. Relationships among the four to five major clades, contingent upon the inclusion of C. sect. microcallis, are strongly supported for the first time. Most species within each clade had similar geographical distributions. However, core C. sect. Androcallis relationships, including most species from Colombia sequenced here, remain unclear. A second goal of this study was to determine the taxonomic status of Calliandra medellinensis. This enigmatic taxon emblematic of Medellín, Colombia, is found in limited numbers within the Aburrá Valley and no populations have been found in the field. For that reason, it has been proposed to be a hybrid taxon. Here, C. magdalenae and C. haematocephala were not monophyletic within the core C. sect. Androcallis clade, while results concerning the monophyly of C. medellinensis are not conclusive. More informative molecular markers should be used in future studies to the determine the status of species for these taxa. Specifically, genomic studies should assess interspecific hybridization demographic models. Such insights can illuminate the C. medellinensis origin, guiding conservation strategies and providing valuable evolutionary overviews.

Parinari is a pantropical genus with 39 species of mostly emergent trees. Nineteen species are found in the Neotropical region, with a taxonomic history complicated by several species complexes and little morphological variation. In this paper, I conducted a taxonomic treatment of species of Parinari that occur in the Brazilian Atlantic Forest, including an identification key, species descriptions, distribution maps, and preliminary conservation status for each taxon. Additionally, new floral characters not previously explored in the taxonomy of the genus are introduced. Four species of Parinari are recognized in the Atlantic Forest, while P. leonthopitheci is synonymized, and names incorrectly applied to the Parinari excelsa complex are investigated. Parinari pohlii, a taxon treated for 50 yr as a synonym of P. brasiliensis, is reestablished, and lectotypes are designated for both names. Preliminary conservation status assessments indicate that three species are likely Endangered (EN): P. alvimii, P. littoralis, and P. pohlii. Finally, I indicate the exclusion from the treatment of two taxa, Parinari excelsa and Parinari parvifolia that do not occur in the Atlantic Forest but were erroneously identified in herbarium collections and in the literature.

Cladocolea (Loranthaceae) is a neotropical genus currently containing 24 species. Its taxonomic history has included changes in its circumscription and the transfers of some of its species to other genera in the family. Several phylogenetic studies of Loranthaceae have recognized a close relationship between Cladocolea and Struthanthus. However, both genera were poorly represented in these studies, so here we generate a phylogeny of Mexican species of Cladocolea, Struthanthus, and related genera of Psittacanthinae, using nuclear DNA sequences of the ITS region, as well as the chloroplast regions matK and trnL-F. The sample includes 112 new sequences and an additional 12 sequences obtained from GenBank. These represent 23 taxa of Cladocolea, 14 of Struthanthus, and 10 from nine other genera of Loranthaceae. In order to understand character evolution and estimate ancestral states, 13 morphological characters were mapped, both vegetative and reproductive. Bayesian inference and Maximum likelihood analyses were performed using independent matrices and a concatenated matrix of 2842 characters. Our results show that Cladocolea and Struthanthus are both polyphyletic genera. However, the Mexican species of Cladocolea and Struthanthus with convolute or sigmoid styles form a monophyletic group. Finally, the analysis of ancestral character states indicates a trend towards a reduction of inflorescences in the Cladocolea-Struthanthus complex. New combinations and synonymies are proposed.

Cladocolea (Loranthaceae) es un género neotropical que actualmente comprende 24 especies. Su historia taxonómica incluye cam-bios en su circunscripción, así como la transferencia de algunas de sus especies a otros géneros de la familia. Varios estudios filogenéticos de Loranthaceae han reconocido una relación cercana entre Cladocolea y Struthanthus. Sin embargo, ambos géneros están escasamente representados en estos estudios, por lo que aquí generamos una filogenia de especies mexicanas de Cladocolea, Struthanthus y otros géneros de Psittacanthinae, usando secuencias de ADN nuclear de la región ITS, así como de las regiones de cloroplasto matK y trnL-F. Ciento doce individuos fueron muestreados y doce secuencias de GenBank fueron incluidas. Estos representan 23 taxa de Cladocolea, 14 de Struthanthus y 10 de otros nueve géneros de la familia Loranthaceae. Para estimar los estados ancestrales y evolución de caracteres, se mapearon 13 caracteres morfológicos vegetativos y reproductivos. Los análisis de Inferencia Bayesiana y Máxima verosimilitud fueron ejecutados usando matrices de datos independientes y una matriz concatenada de 2842 caracteres. Los resultados muestran que Cladocolea y Struthanthus son géneros polifiléticos. Sin embargo. Las especies mexicanas de Cladocolea y Struthanthus con estilo convoluto o sigmoide forman un grupo monofilético. Finalmente, el análisis de estados ancestrales de carácter indica una tendencia a la reducción de las inflorescencias en el complejo Cladocolea-Struthanthus. Se proponen nuevas combinaciones y sinonimias.

Monotropoideae (Ericaceae) is a wholly leafless and holomycotrophic group of primarily temperate herbs with centers of diversity in western North America and east Asia. The eleven genera are structurally diverse and also vegetatively reduced, making relationships difficult to assess based on morphology. Previous molecular analyses have focused primarily on segments of the ribosomal RNA repeat and yielded sometimes conflicting topologies. We employed a genomic sampling approach to obtain 102 nuclear loci and plastid coding loci for nine of the genera, as well as sampling ITS-26S and plastid rps2 for a broader set of accessions via PCR and Sanger sequencing. Data filtering for character completeness had a clear effect on relationships and branch support. Nuclear and plastid loci agree on a topology that resolves Allotropa and Hemitomes as sisters and Monotropsis sister to Eremotropa+Monotropa+Monotropastrum, relationships that were unclear from previous analyses. Hypopitys should be recognized as distinct from Monotropa, with previous ambiguity in rps2 relationships here explained by the existence of plastid and mitochondrial paralogs. Comparison of branch lengths between nuclear and plastid loci reveals increased rates of change in plastid sequences in most cases, especially in Monotropsis and Monotropa, but the reverse situation in Pityopus, with nuclear branches being unusually long, possibly indicating cryptic diversity. Parallel shifts in plant form to a ground-level floral display correlate with shifts from capsular to berry fruits and reduction in species ranges. The optimal tree from molecular data requires significant parallelism and/or reversal in morphological features due to the placement of Allotropa and Hemitomes.

Ternstroemia is a genus with ca. 141 species, of which 87–103 are present in the Neotropics. As part of the studies of the genus in Colombia, here we propose four new species: Ternstroemia pacifica (from Chocó), T. fandango (Caribe-Cordillera Central transition), T. cachalu, and T. religiosa (both from Cordillera Oriental). Ternstroemia pacifica and T. fandango show morphological affinities with Amazonian species, T. cachalu with a Central Andean species, and T. religiosa present no clear affinities. Since some species have been either excluded or included for the country in literature, we clarify how many species occur in Colombia. From a total of 21 recorded species, we exclude the presence of six. After the present revision, Colombia harbors 18 species of Ternstroemia, nine (i.e. 50%) of which are endemic. Illustrations, color plates, distribution maps, and notes on ecology, habitat, and conservation status are provided for the four new species, as well as habitat, geographic distribution, biogeographic province, and global distribution for the remaining ones. An actualized key for the taxa growing in the country is also included.

Ternstroemia es un género con ca. 141 especies, de las cuales 87–103 están presentes en el Neotrópico. Como parte de los estudios del género en Colombia, proponemos aquí cuatro especies nuevas: Ternstroemia pacifica (Chocó), T. fandango (transición Caribe-Cordillera Central), T. cachalu y T. religiosa (ambas de la Cordillera Oriental). Ternstroemia pacifica y T. fandango muestran similitudes morfológicas con especies amazónicas, T. cachalu con una especie de los Andes centrales, y T. religiosa no presenta afinidades claras. Algunas especies han sido excluidas o incluidas en la literatura para el país, por lo que aclaramos cuántas de estas se encuentran realmente en Colombia. De las 21 especies reportadas hasta ahora, excluimos la presencia de seis. Colombia alberga, luego de la presente revisión, 18 especies de Ternstroemia, nueve de ellas (i.e.: 50%) endémicas. Se proporcionan ilustraciones, planchas a color, mapas de distribución, notas sobre ecología, hábitat y estado de conservación para las especies nuevas, y hábitat, distribución geográfica, provincia biogeográfica y distribución global para las restantes. Adicionalmente, se incluye una clave actualizada para los taxones que se encuentran creciendo en el país.

Paraphlomis octopus (Lamiaceae), a new species from the limestone area in Guangdong and Guangxi, China, is described and illustrated. Molecular phylogenetic analyses based on two nuclear ribosomal DNA sequences revealed that the new species is sister to P. pagantha, and the two species is further sister to P. kwangtungensis. All three species were further embedded within a clade consisting of species with hairy ovaries or nutlets. Morphologically, the new species can be distinguished from P. kwangtungensis in its acute apex of calyx tooth, from P. pagantha in its strongly reflexed lower corolla lip, and from both species in its inflorescence with peduncle-like stalks, and wider upper corolla lip. Based on extensive field survey, we also found that the type locality of P. kwangtungensis has long been misrecorded as eastern Guangdong in floras. The species is now only known from its actual type locality in Fengwan Town, northern Guangdong. A key to all species with hairy ovaries and nutlets is provided.

Agalinis (Orobanchaceae, tribe Pedicularideae) consists of approximately 70 hemiparasitic species distributed among North, Central, and South America. Previous phylogenetic studies did not include tropical species nor comprehensive sampling for closely allied genera, limiting our systematic understanding of these lineages. We generated an updated phylogenetic hypothesis from 179 individuals from 51 species of Agalinis and five genera once considered congeneric with Agalinis (Anisantherina, Brachystigma, Dasistoma, Aureolaria, and Esterhazya), particularly focusing on sampling underrepresented Central and South American taxa. Phylogenetic analyses were based on six cpDNA regions (rbcL, matK, trnT(UGU)-trnF(GAA), rps2, rpoB, and psbA-trnH) and four nuclear regions (ITS, PPR-AT1G09680, PPR-AT3G09060, and PPR-AT5G39980) and were conducted using maximum likelihood and Bayesian inference methods. Additionally, our data were added to previously published Orobanchaceae-wide datasets to reveal placement of these lineages in a comprehensive phylogenetic context using maximum likelihood. Our results reveal a strongly supported South American Agalinis clade that is sister to taxa from southwestern North America and Mexico and includes distinct Brazilian and Andean clades. Esterhazya, a hummingbird-pollinated genus in Brazil, is nested within the Brazilian Agalinis clade with strong support. We confirm well-supported incongruences between chloroplast and nuclear partitions, particularly concerning placement of early-diverging lineages within Agalinis. The monotypic genus Anisantherina, once included in Agalinis, is resolved within Orobanchaceae tribe Buchnereae, a placement that is further corroborated by anther morphology. Orobanchaceae consist of numerous species from tropical regions that have not been included in phylogenetic studies, and our study underscores the importance of more comprehensive sampling for the placement of these lineages to clarify taxonomy, biogeography, and character evolution.

Field and phylogenetic studies of Collinsia previously resulted in discovery of the distinctive “metamorphica” clade from metamorphic scree of the upper Merced River drainage on the western slope of the central Sierra Nevada, California. The three component lineages within this clade are described here as new species: C. metamorphica from the South Fork Merced River watershed, C. parkii from Trumbull Peak, and C. wakahlmae from the Merced River canyon in the vicinity of El Portal. These new taxa, first collected in the 1980s, have been confused with C. childii, C. linearis, and C. rattanii. Collectively, the three new taxa can be distinguished from C. childii by their narrower mid- to distal-stem leaves, and, in fruit, their much less recurved to erect calyx lobes that are not longer than the capsule, or not conspicuously so. They are distinguishable from C. linearis and C. rattanii by their non-revolute leaf margins and capsules with only two seeds. The three new taxa differ in part from one another by a combination of corolla color, size, and shape, calyx length, and leaf blade shape. These morphologically and geographically distinctive taxa provide additional evidence for angiosperm diversification within the upper Merced River watershed and collectively have distributions similar to those of some other endemics of the area that co-occur on metamorphic scree exposures. Further exploration of these habitats for undescribed plant diversity and any undiscovered populations of these rare new taxa is warranted, as is their immediate protection from potential threats.

The neotropical physaloid genera Witheringia and Brachistus have long been subject to taxonomic confusion. We obtained tissue from well-documented species of these genera, including multiple accessions from widespread taxa, to generate a molecular systematic framework. We present Bayesian phylogenies based on sequences of one chloroplast (trnL-trnF) and two nuclear loci (ITS and waxy). The major findings are that: 1) Witheringia and Brachistus together form a well-supported monophyletic group, 2) Brachistus is nested within Witheringia, 3) two Mexican endemic species represent the earliest diverging lineages of the clade, 4) several proposed synonyms represent distinct species, and 5) sequenced accessions include several new species awaiting description. The four currently recognized species of Brachistus are transferred to Witheringia, necessitating the new combination Witheringia knappiae, and Athenaea affinis is lectotypified. A list is also provided for names now excluded from Brachistus and recognized as belonging to other genera.

Los géneros neotropicales de physaloid Witheringia y Brachistus han sido durante mucho tiempo objeto de confusión taxonómica. Obtuvimos tejidos de especies bien documentadas de estos géneros, incluyendo múltiples adiciones de taxones muy extendidos, para generar un marco sistemático molecular. Presentamos filogenias bayesianas basadas en las secuencias de un cloroplasto (trnL-trnF) y dos loci nucleares (ITS y waxy). Los principales hallazgos son que: 1) Witheringia y Brachistus forman juntos un grupo monofilético bien apoyado, 2) Brachistus sale dentro de Witheringia, 3) dos especies endémicas mexicanas representan los linajes divergentes más tempranos del clado, 4) varios sinónimos propuestos representan especies distintas, y 5) las adiciones secuenciadas incluyen varias especies nuevas pendientes de descripción. La filogenia proporcionará un valioso marco para futuros trabajos sobre sistemática, evolución de los caracteres y biogeografía. Las cuatro especies de Brachistus actualmente reconocidas se transfieren a Witheringia, lo que requiere la nueva combinación Witheringia knappiae, y Athenaea affinis está lectotipificada. También se proporciona una lista de nombres ahora excluidos de Brachistus y reconocidos como pertenecientes a otros géneros.

Dubautia haupuensis is newly described from windswept ridgelines near the summit of Hā‘upu, in an isolated range noted for floristic endemism on Kaua‘i, in the Hawaiian Islands, where only two clusters of plants are currently known. Based on molecular phylogenetic data, this highly endangered shrub of the Hawaiian silversword alliance belongs to a recently resolved clade of endemic Kaua‘i taxa, mostly from wet or bog habitats, including D. imbricata subsp. acronaea, D. imbricata subsp. imbricata, D. kalalauensis, D. kenwoodii, D. laevigata, D. syndetica, and D. waialealae. Unlike its close relatives and other members of Dubautia, D. haupuensis has the following unique combination of morphological characteristics: well-branched shrubs with leaves opposite, sessile, and glabrous, leaf venation ± parallelodromous, with 5 to 9 basal nerves, capitulescences densely corymbiform to paniculiform, peduncles hirsute, peduncular bracts lance-linear to ovate, with faces glabrous and margins ciliate, heads 7- to 12-flowered, paleate throughout, the paleae each partially clasping a floret, with faces glabrous and distal margins ciliate, corolla tube/throat sessile-glandular, the throat dilated ≤ 2 × tube width, and pappus ± equaling corolla, of 20 to 31 setiform to narrowly subulate, densely ciliate scales, the cilia < 0.5 mm long. It also is distinguished from all other taxa of the silversword alliance by diagnostic nuclear ribosomal DNA nucleotide states. Six of the seven taxa that constitute a clade with D. haupuensis have highly restricted distributions on Kaua‘i and are of significant conservation concern, as reflected by listing of most of them as Endangered by the U.S. Fish and Wildlife Service. Dubautia haupuensis is also exceedingly rare and in need of immediate conservation action to prevent its extinction. Invasive plants (especially melastomes), potential ungulate activity, lack of opportunity for outcrossing, and any mortality from stochastic events are major threats to the species, in addition to possible impacts of anthropogenic climate change.