Macroevolution of the plant-hummingbird pollination system.

Plant-hummingbird interactions are considered a classic example of coevolution, a process in which mutually dependent species influence each other's evolution. Plants depend on hummingbirds for pollination, whereas hummingbirds rely on nectar for food. As a step towards understanding coevolution, this review focuses on the macroevolutionary consequences of plant-hummingbird interactions, a relatively underexplored area in the current literature. We synthesize prior studies, illustrating the origins and dynamics of hummingbird pollination across different angiosperm clades previously pollinated by insects (mostly bees), bats, and passerine birds. In some cases, the crown age of hummingbirds pre-dates the plants they pollinate. In other cases, plant groups transitioned to hummingbird pollination early in the establishment of this bird group in the Americas, with the build-up of both diversities coinciding temporally, and hence suggesting co-diversification. Determining what triggers shifts to and away from hummingbird pollination remains a major open challenge. The impact of hummingbirds on plant diversification is complex, with many tropical plant lineages experiencing increased diversification after acquiring flowers that attract hummingbirds, and others experiencing no change or even a decrease in diversification rates. This mixed evidence suggests that other extrinsic or intrinsic factors, such as local climate and isolation, are important covariables driving the diversification of plants adapted to hummingbird pollination. To guide future studies, we discuss the mechanisms and contexts under which hummingbirds, as a clade and as individual species (e.g. traits, foraging behaviour, degree of specialization), could influence plant evolution. We conclude by commenting on how macroevolutionary signals of the mutualism could relate to coevolution, highlighting the unbalanced focus on the plant side of the interaction, and advocating for the use of species-level interaction data in macroevolutionary studies.

ATLANTIC POLLINATION: a data set of flowers and interaction with nectar-feeding vertebrates from the Atlantic Forest.

Flowering plant species and their nectar-feeding vertebrates exemplify some of the most remarkable biotic interactions in the Neotropics. In the Brazilian Atlantic Forest, several species of birds (especially hummingbirds), bats, and non-flying mammals, as well as one lizard feed on nectar, often act as pollinators and contribute to seed output of flowering plants. We present a dataset containing information on flowering plants visited by nectar-feeding vertebrates and sampled at 166 localities in the Brazilian Atlantic Forest. This dataset provides information on 1902 unique interactions among 515 species of flowering plants and 129 species of potential vertebrate pollinators and the patterns of species diversity across latitudes. All plant-vertebrate interactions compiled were recorded through direct observations of visits, and no inferences of pollinators based on floral syndromes were included. We also provide information on the most common plant traits used to understand the interactions between flowers and nectar-feeding vertebrates: plant growth form, corolla length, rate of nectar production per hour in bagged flowers, nectar concentration, flower color and shape, time of anthesis, presence or absence of perceptible fragrance by human, and flowering phenology as well as the plant's threat status by International Union for Conservation of Nature (IUCN) classification. For the vertebrates, status of threat by IUCN classification, body mass, bill or rostrum size are provided. Information on the frequency of visits and pollen deposition on the vertebrate's body is provided from the original source when available. The highest number of unique interactions is recorded for birds (1771) followed by bats (110). For plants, Bromeliaceae contains the highest number of unique interactions (606), followed by Fabaceae (242) and Gesneriaceae (104). It is evident that there was geographical bias of the studies throughout the southeast of the Brazilian Atlantic Forest and that most effort was directed to flower-hummingbird interactions. However, it reflects a worldwide tendency of more plants interacting with birds compared with other vertebrate species. The lack of similar protocols among studies to collect basic data limits the comparisons among areas and generalizations. Nevertheless, this dataset represents a notable effort to organize and highlight the importance of vertebrate pollinators in this hotspot of biodiversity on Earth and represents the data currently available. No copyright or proprietary restrictions are associated with the use of this data set. Please cite this data paper when the data are used in publications or scientific events.

Heterochromatin and numeric chromosome evolution in Bignoniaceae, with emphasis on the Neotropical clade Tabebuia alliance.

Bignoniaceae is a diverse family composed of 840 species with Pantropical distribution. The chromosome number 2n = 40 is predominant in most species of the family, with n = 20 formerly being considered the haploid base number. We discuss here the haploid base number of Bignoniaceae and examine heterochromatin distributions revealed by CMA/DAPI fluorochromes in the Tabebuia alliance, as well as in some species of the Bignonieae, Tecomeae, and Jacarandeae tribes. When comparing the chromosome records and the phylogenies of Bignoniaceae it can be deduced that the base number of Bignoniaceae is probably n = 18, followed by an ascendant dysploidy (n = 18 → n = 20) in the most derived and diverse clades. The predominant heterochromatin banding patterns in the Tabebuia alliance were found to be two terminal CMA+ bands or two terminal and two proximal CMA+ bands. The banding pattern in the Tabebuia alliance clade was more variable than seen in Jacarandeae, but less variable than Bignonieae. Despite the intermediate level of variation observed, heterochromatin banding patterns offer a promising tool for distinguishing species, especially in the morphologically complex genus Handroanthus.

Karyotype analysis in Bignonieae (Bignoniaceae): chromosome numbers and heterochromatin.

Chromosome numbers and heterochromatin banding pattern variability have been shown to be useful for taxonomic and evolutionary studies of different plant taxa. Bignonieae is the largest tribe of Bignoniaceae, composed mostly by woody climber species whose taxonomies are quite complicated. We reviewed and added new data concerning chromosome numbers in Bignonieae and performed the first analyses of heterochromatin banding patterns in that tribe based on the fluorochromes chromomycin A3 (CMA) and 4'-6-diamidino-2-phenylindole (DAPI). We confirmed the predominant diploid number 2n = 40, as well as variations reported in the literature (dysploidy in Mansoa [2n = 38] and polyploidy in Dolichandra ungis-cati [2n = 80] and Pyrostegia venusta [2n = 80]). We also found a new cytotype for the genus Anemopaegma (Anemopaegma citrinum, 2n = 60) and provide the first chromosome counts for five species (Adenocalymma divaricatum, Amphilophium scabriusculum, Fridericia limae, F. subverticillata, and Xylophragma myrianthum). Heterochromatin analyses revealed only GC-rich regions, with six different arrangements of those bands. The A-type (one large and distal telomeric band) were the most common, although the presence and combinations of the other types appear to be the most promising for taxonomic studies.

Karyotype analysis in Bignonieae (Bignoniaceae): chromosome numbers and heterochromatin

ABSTRACT Chromosome numbers and heterochromatin banding pattern variability have been shown to be useful for taxonomic and evolutionary studies of different plant taxa. Bignonieae is the largest tribe of Bignoniaceae, composed mostly by woody climber species whose taxonomies are quite complicated. We reviewed and added new data concerning chromosome numbers in Bignonieae and performed the first analyses of heterochromatin banding patterns in that tribe based on the fluorochromes chromomycin A3 (CMA) and 4'-6-diamidino-2-phenylindole (DAPI). We confirmed the predominant diploid number 2n = 40, as well as variations reported in the literature (dysploidy in Mansoa [2n = 38] and polyploidy in Dolichandra ungis-cati [2n = 80] and Pyrostegia venusta [2n = 80]). We also found a new cytotype for the genus Anemopaegma (Anemopaegma citrinum, 2n = 60) and provide the first chromosome counts for five species (Adenocalymma divaricatum, Amphilophium scabriusculum, Fridericia limae, F. subverticillata, and Xylophragma myrianthum). Heterochromatin analyses revealed only GC-rich regions, with six different arrangements of those bands. The A-type (one large and distal telomeric band) were the most common, although the presence and combinations of the other types appear to be the most promising for taxonomic studies.

Studies in regard to the classification and putative toxicity of Fridericia japurensis (Arrabidaea japurensis) in Brazil.

Numerous plant species worldwide including Palicourea marcgravii (Rubiaceae) and Tanaecium bilabiatum (Bignoniaceae) in Brazil cause acute cardiac failure (sudden death) and are known to contain monofluoroacetate (MFA). Other Bignoniaceae species including Fridericia japurensis (Arrabidaea japurensis) are reported to cause sudden death in livestock in the Brazilian state of Roraima and are suspected to contain MFA due to the similarity of clinical signs. In this study herbarium specimens of Fridericia japurensis and field collections suspected to be F. japurensis were analyzed for MFA, and plant material from the field collections was dosed to rabbits. No MFA was detected in the herbarium specimens authoritatively identified as F. japurensis; however, MFA was detected in the field collections, which were identified as T. bilabiatum. Rabbits dosed orally with T. bilabiatum died acutely. Voucher toxic specimens initially described as F. japurensis were incorrectly identified, and the correct botanical name for this plant is T. bilabiatum (Arrabidaea bilabiata). Based on this study we conclude that there are no data to support the toxicity of F. japurensis and that the plant previously reported under this name as causing acute cardiac failure in cattle in Roraima is T. bilabiatum. This research highlights the importance of voucher specimens as part of any toxic plant investigation and corrects the literature regarding these toxic plants.