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This paper aims to integrate cytogenetic and ecological approaches into a phylogenetic framework to better understand the evolution and systematics of Senna series Aphyllae , an endemic group of arid and semi-arid regions of South America. We counted the chromosome numbers at the population level in three species of series Aphyllae using a conventional technique (GIEMSA) and in situ hybridization (FISH). Phylogenetic reconstructions and inference of chromosome evolution were based on four plastid DNA regions and one nuclear marker. A principal component analysis was carried out using environmental data. Finally, ecological niche models (ENM) were implemented: (1) to identify the abiotic factors that constraint the potential geographical distribution of series Aphyllae and (2) to understand the ecological drivers for species diversification. The basic chromosome number is x = 12. Senna aphylla showed three cytotypes with (2 n = 24, 48 and 60) and S. pachyrrhiza has two cytotypes (2 n = 24 and 48). Senna crassiramea appeared to be polyploid with 2 n = 48. In diploid S. pachyrrhiza , two 45S and three 5S rDNA sites were reported. In tetraploid S. crassiramea , four 45S and four 5S rDNA sites were detected. The ENM and ecological speciation tests suggest that in series Aphyllae speciation was sometimes associated with conservatism and sometimes with niche divergence. Our results contribute to the evolutionary knowledge of Neotropical legumes and understanding of drivers of diversification in arid regions in South America. [ABSTRACT FROM AUTHOR]

Seven species of three are recognised in the genus Peltophorum , distributed in the tropics and subtropics of America, South Africa, Asia, and Oceania. These species are used as ornamentals, restorers of degraded ecosystems, and forestry, providing commercially valuable wood. This review aims to analyse the different records of biological activity reported for the genus. Bibliographic searches were conducted across various recognised databases, including Google Scholar, PubMed, Scopus, ScienceDirect, and Portal da Periódicos da CAPES. The searches encompassed articles, research theses, and books specifically addressing ethnobotany, isolated chemical constituents, and bioactivities within Peltophorum species. The exploration covered the years 1982–2023, and the connectors 'and' and 'or' were used. The total number of articles on the genus Peltophorum evaluated was 85, with seven excluded based on the editor's requirements and the nature of the research. This study comprehensively investigated the seven taxonomically recognised species, documenting the activities of synonyms and updating their nomenclatural binomials under the International Plant Names Index (IPNI). The review considered the diverse biological activities associated with these species, encompassing antiparasitic, antibacterial, antifungal, antiviral, anticancer, anti-inflammatory, antioxidant, antimutagenic, and traditional medicinal uses such as analgesic, hepatoprotective, and cardioprotective effects, among others. Analysis of phytochemical groups linked to different bioactivities revealed a predominance of phenolic compounds, coumarins, flavonoids, saponins, and tannins. A detailed review of the Peltophorum genus was presented, inclusive of the phytochemical background, as well as various pharmacological and ethnobotanical activities. This contribution provides valuable information for future research. • The representatives have utility as ornamentals, re-constituents of degraded and forestry ecosystems, providing wood of commercial value. • These species stand out for their antecedents of different biological activities: antiparasitic, antibacterial, antifungal, antiviral, anticancer, antiinflammatory, antioxidant, antimutagenic and uses in traditional medicine: analgesic, hepatoprotective, cardioprotective, among others. • The phytochemical references related to the different bioactivities are, for the most part, phenolic compounds, coumarins, flavonoids, saponins and tannins. • All these characteristics of the species of this genus make it stand out and are interesting for study. [ABSTRACT FROM AUTHOR]

Senna series Aphyllae includes xeromorphic shrubs and subshrubs that occur in three different biogeographic subregions in arid and semi-arid habitats of southern South America. The series provides a good opportunity to understand better the relationship among geographical, climatic, and morphological variation in different taxa. Moreover, in this group the specific and varietal delimitation is still problematic due to the high morphological variation within and among taxa. Statistical analyses of climatic and morphological data and geographical distribution were used to understand the patterns of morphological variation among 394 individuals and to clarify the taxonomic delimitation of entities that belong to series Aphyllae. Senna acanthoclada and S. nudicaulis were segregated from each other and from the remaining taxa; the three recognized varieties of the S. aphylla complex were delimited; S. spiniflora was well-delimited and S. crassiramea and S. rigidicaulis were overlapping; S. pachyrrhiza was not differentiated from S. aphylla. Ecological niche modelling showed several areas of contact and a large overlap of suitable conditions for several species. The results of this work revealed that most morphological variability is associated with different environmental conditions. This phenotypic plasticity may be caused by the presence of different environments with climatic factors in the South American Transition Zone, Chaco, and northern region of Central Patagonia province. [ABSTRACT FROM AUTHOR]

Balsamocarpon, Lophocarpinia, Stenodrepanum and Zuccagnia are monospecific endemic genera from arid or saline areas of southern South America (Argentina, Paraguay, Chile). Several molecular studies have explored relationships within Caesalpinioideae and the Caesalpinia group but, until now, Stenodrepanum has not been included, Lophocarpinia has been poorly represented and these four South American taxa have not been analyzed together. In order to resolve their evolutionary relationships, a phylogenetic analysis of the plastid trnL-F intron and spacer region that included a broad range of published sequences from Caesalpinieae was used. Combined trnL-F, matK/trnK and morphological data were analysed for a subset of taxa. Stenodrepanum, Balsamocarpon and Zuccagnia formed a monophyletic group with the amph ¡tropical American genus Hoffmannseggia. The clade shares a synapomorphy of sepal persistence in the fruit. Lophocarpinia is shown also to belong to the Caesalpinia informal generic group as traditionally proposed, and grouped with Haematoxylum with which it shares the presence of branches and inflorescences crowded on short shoots and spines derived from branches. As a contribution to the understanding of the Caesalpinia group, phylogenetic hypotheses were used to discuss evolution of selected characters within the group. [ABSTRACT FROM AUTHOR]

Bauhinia affinis Vogel is reported for the first time in the NE extreme of Argentina. The number of species of the genus recorded for the country is increased to 7. The species is described and illustrated indicating its geographic distribution; its affinities with the related species are discussed and a diagnostic key for its identification in Argentine flora is included. [ABSTRACT FROM AUTHOR]