Heliconia (Heliconiaceae) is a genus of giant rhizomatous herbs that have bright and striking bract inflorescences. The family consists of one genus and about 194 species that occur naturally in the tropical regions of the world, concentrating their greatest diversity and endemism in the Andean foothills and the Pacific region of Colombia, with approximately 120 species of the total registered for the world. Within the species of this genus there is high morphological variation, which sometimes makes clear identification of Heliconia specimens difficult. So is the case of Heliconia platystachys Baker, which contains two morphologically distinct groups of plants distinguished by the size and color of the bracts, the floral bracts, the mucilage that covers the flowers, and the shape of the staminodium. These structures of floral biology such as staminodium are of great taxonomic value in the study of the species within the genus Heliconia. The main goal of this work was to study Heliconia populations, which are found on the western slope of the Central Cordillera of Colombia at elevations between 970 and 1200 m, for which the morphoanatomical and palynological attributes were analyzed. We want to explore in this work whether the variation exhibited by these populations and their distribution allows us to postulate the occurrence of a new species with sufficient evidence for its separation.

The subfamily Caesalpiniodeae has been the subject of several recent taxonomic delimitations, placing Mimosa in what is recognized as the “Mimosa clade.” Specifically, in recent decades several phylogenetic studies have been conducted with regard to the genus, but the estimation of the divergence times of some previously unanalyzed species was unknown and the reconstruction of ancestral morphological states to date has been limited to the mapping of characters on a phylogenetic tree. The aim of the present study was to perform a phylogeny based on the trnD₂-trnT and rpS16 cpDNA markers as well as 19 morphological characters. We use these results to estimate the divergence times for Mimosa including some species not previously analyzed. In addition, we reconstructed the ancestral states using a chronogram for eight morphological characters: 1) leaf nectaries, 2) brachyblasts, 3) stamens, 4) staminodes, 5) type of flower, 6) type of inflorescence, 7) fruit dehiscence, and 8) fruit shape. Our results suggest that Mimosa originated in the Americas during the late Oligocene and that the genus shows recent diversification and numerous lineages in Mexico and South America, especially after the Pliocene and up to the present. The reconstruction of ancestral states reveals the tendency of the most recently divergent species toward reduction in flower parts and in some cases the preservation of plesiomorphic morphological character states.

Piper (Piperaceae) is a species-rich pantropical genus (∼2000 species) with distinctive morphological characteristics such as swollen nodes, lack of a perianth, and one-seeded berry fruits. Sub-generic lineages within Piper are often associated with morphological traits and are well supported with molecular data, but sampling in previous studies was incomplete and conflict exists between morphological data and molecular inference. In this paper, Piper section Enckea is evaluated for monophyly by pairing DNA, primarily from herbarium material, with the Angiosperms353 bait set, high throughput sequencing, recently developed bioinformatic techniques, and two methods of phylogenetic reconstruction, maximum likelihood and multi-species coalescence. The results suggest continued support for recognition of Piper sect. Enckea as a monophyletic section and contribute to a better understanding of relationships among species within the section. However, they also raise questions about the morphological features used to define P. sect. Enckea and delimit species within the section.

In this study we explore the biogeographic patterns and processes underlying the diversification of Sabal, a genus of palm with a range that expands from the tropical rainforests of northern South America into the deciduous subtropical forests of the southeastern United States. We estimate divergence times among species of Sabal using two dated fossils as calibration points to inform ancestral reconstructions of the historical distribution of Sabal, and then use floral volatile composition data in select species of Sabal to integrate plant ecological interactions into our discussion of species distributions. Our results suggest extant Sabal originated within the last 21 million years with a divergence event ∼14 million years ago that effectively split the most recent common ancestor of all southeastern United States and West Indian species from the ancestor of a clade of species with their current distribution in Mexico. This divergence event corresponds with the end of the mid-Miocene climatic optimum, which resulted in cooler climates across southeastern North America where extant cold-tolerant taxa S. minor and S. palmetto are currently distributed. Floral volatile data indicate a generalist pollination strategy involving day foraging insects. Among sampled species, floral scent profiles can mostly be characterized by quantitative differences in five main compounds: benzaldehyde, benzyl alcohol, 2-phenylethanol, (E)-β-ocimene, and hexanal. These profiles align with major clades recovered in our phylogenetic analysis of Sabal and are indicative of evolutionary trends in pollination ecology and reproductive isolation within the genus.

Podostemaceae are a clade of aquatic flowering plants that form important components of tropical river ecosystems. Species in the family exhibit highly derived growth forms and high vegetative phenotypic plasticity, both of which contribute to taxonomic confusion. The backbone phylogeny of the family remains poorly resolved, many species remain to be included in a molecular phylogenetic analysis, and the monophyly of many taxa remains to be tested. To address these issues, we assembled sequence data for 73 protein-coding plastid genes from 132 samples representing 68 species (∼23% of described species) that span the breadth of most major taxonomic, morphological, and biogeographic groups of Podostemaceae. With these data, we conducted the first plastid phylogenomic analysis of the family with broad taxon sampling. These analyses resolved most nodes with high support, including relationships not recovered in previous analyses. No evidence of widespread, well-supported conflict among individual plastid genes and the concatenated phylogeny was observed. We present new evidence that four genera (Apinagia, Marathrum, Oserya, and Podostemum), as well as four species, are not monophyletic. In particular, we show that Podostemum flagelliforme should not be included in Podostemum and is better recognized as Devillea flagelliformis, and that Marathrum capillaceum is embedded within Lophogyne s.l. and should be recognized as Lophogyne capillacea. We also place a previously unsampled and undescribed species that likely represents a new genus. In contrast to previous studies, the neotropical genera Diamantina, Ceratolacis, Cipoia, and Podostemum are resolved as successive sister groups to a clade of all paleotropical Podostemoideae taxa sampled, suggesting a single dispersal event from the neotropics to the paleotropics in the history of the subfamily. These results provide a strong basis for improving the classification of Podostemaceae and a framework for future phylogenomic studies of the clade employing data from the nuclear genome.

The genus Genipa is a widespread, lowland, Neotropical lineage of trees in the coffee family, Rubiaceae. There is long-standing disagreement on the delimitation of species in the genus and how broadly Genipa is circumscribed. Here, we use genomic data to resolve the classification within Genipa. Using target sequence capture we generated a high-resolution 245-locus dataset to produce a comprehensive species phylogeny under the multi-species coalescent model. The phylogenomic results strongly support Genipa spruceana, often synonymised with Genipa americana, as a distinct monophyletic species. Similarly, the monophyly of Genipa infundibuliformis, a recently recognized species, is also strongly supported. The phylogeny also shows three distinct, well-supported clades within the widespread species, Genipa americana. These clades are interpreted as three independently evolving lineages in contrast to the two varieties most commonly recognized in G. americana based on previous morphological studies.

Molecular phylogenetic studies have been the basis for major clades proposed for the Aeridinae subtribe of the Orchidaceae family. However, systematic morphological characterization has yet to be conducted. We carried out this study on Aeridinae pollinium morphologies with an emphasis on aperture type and pollinium sculpturing to determine the systematic significance of these characteristics in the context of molecular phylogenetics. The results indicated that most Aeridinae species have cleft type pollinium apertures and that few have porate type or no aperture. The shapes of most of the pollinia were flat but this was not consistent at the genus level. Pollinium length ranged from 204 to 2606 mm, and the width from 178 to 1524 mm. Long and wide pollinia were commonly found in primitive groups, while short and narrow pollinia were commonly found in evolutionarily derived groups. The shapes and sizes of the individual units of the pollinia varied from uniform to variable, with a few exceptions. The individual units of most the pollinia were tetrads, and individual pollen grains were easily distinguished within the tetrad. The degree to which individual pollen grains could be differentiated is constant at the clade level except for Aerides rosea. The exine sculpturing characteristics were consistent in each clade except in the Cleisostoma and Phalaenopsis clades. The pollinium sculpturing has a somewhat clear pattern of change that was consistent with the molecular phylogeny, with a few exceptions. In conclusion, these pollinium characteristics themselves are not systematic, but they can serve as useful characteristics for determining the major systematic groups in the subtribe Aeridinae.

Sanvitalia (Asteraceae), a New World endemic, is poorly understood from a phylogenetic perspective. While chromosome number variation is well documented for the genus, previous studies lack a phylogenetic context for chromosome number evolution, with one species, S. fruticosa, lacking a published chromosome count. We collected molecular sequence data from the nuclear ribosomal ITS region and three plastid loci from multiple individuals of each species of Sanvitalia and additional members of the Zinniinae to create phylogenetic trees and study the evolutionary history of the clade. A complete taxonomic treatment was produced as well as a dichotomous key to species. The first chromosome count for S. fruticosa was rendered (2n = 16) and a chromosome number analysis was completed using maximum likelihood methods that account for different modes of chromosome number change. Support for two separate whole genome duplication events in the genus is presented here. This study resulted in deeper understanding of the relationships within Sanvitalia and closely related genera, chromosome number evolution and genome duplication in Zinniinae, and the closest relative (S. ocymoides) of the enigmatic and amphiequatorial disjunct S. versicolor. We also provide support for the prior transfer of S. tenuis to Zinnia, and two new sections within Sanvitalia.

Sanvitalia (Asteraceae), un endémico del Nuevo Mundo, es poco comprendido desde una perspectiva filogenética. Si bien la variación del número de cromosomas está bien documentada para el género, estudios previos carecen de un contexto filogenético para la evolución del número de cromosomas, y una especie, S. fruticosa, carece de un recuento de cromosomas publicado. Recopilamos datos de secuencia molecular de la región ITS del ribosoma nuclear y tres loci de plástidos de múltiples individuos de cada especie de Sanvitalia y miembros adicionales de Zinniinae para crear árboles filogenéticos y estudiar la historia evolutiva del clado. Se produjo un tratamiento taxonómico completo así como una clave dicotómica para especies. Se realizó el primer recuento de cromosomas para S. fruticosa (2n = 16) y se completó un análisis del número de cromosomas utilizando métodos de máxima verosimilitud que tienen en cuenta diferentes modos de cambio en el número de cromosomas. Aquí se presenta el soporte para dos eventos separados de duplicacióndel genoma completo en el género. Este estudio resultó en una comprensión más profunda de; las relaciones dentro de Sanvitalia y géneros estrechamente relacionados, la evolución del número de cromosomas y la duplicación del genoma en Zinniinae, y el pariente más cercano (S. ocymoides) del enigmático y anfiequatorial disyuntiva S. versicolor. También brindamos apoyo para la transferencia previa de S. tenuis a Zinnia, y dos nuevas secciones dentro del Sanvitalia.

Cuscuta section Indecorae is an infrageneric clade of Cuscuta subgenus Grammica that originated in North America which includes three species: C. indecora, C. coryli, and C. warneri. Some forms of C. indecora are agricultural weeds, while C. warneri and C. coryli face conservation problems regionally or globally. Cuscuta indecora is a morphologically diverse species with three recognized varieties: C. indecora var. indecora, C. indecora var. longisepala, and C. indecora var. attenuata. Two recent broad-scale molecular phylogenetic studies raised questions about the circumscription of C. indecora and the validity of its infraspecific taxa. Therefore, we conducted an extensive morphometric study, and used DNA sequences from plastid and nuclear ribosomal non-coding regions to reconstruct evolutionary relationships among taxa. In addition, we studied the host range of all taxa using herbarium specimens, bipartite networks, and Venn diagrams. Results from all types of evidence confirmed the circumscription of the three species, but differed on the infraspecific structure of C. indecora. The molecular phylogeny inferred C. indecora as paraphyletic, consisting of two distinct clades, with C. coryli nested within one of them. The morphometric and host range studies uncovered extensive overlaps both among the traditional varieties of C. indecora as well as between the two molecular lineages of C. indecora. Previously, Iva annua had been considered the sole host of C. indecora var. attenuata (C. attenuata) and this presumed host specificity was the main criterion for accepting this taxon. We found that the type of C. indecora var. longisepala was also growing on Iva annua, which together with the morphological and genetical similarity, indicates that C. indecora var. attenuata is identical to C. indecora var. longisepala. Overall, considering the lack of morphological, host range, and geographical patterns distinguishing either the current three varieties of C. indecora or the two cryptic lineages, the most appropriate solution is to tentatively recognize C. indecora as variable species without recognizing any infraspecific taxa.