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Sisyrinchium, a large genus of the Iridaceae family, is divided into ten sections and defined by genetic, morphological and phylogenetic traits. The section Viperella, though monophyletic, encounters taxonomic hurdles, particularly within the Sisyrinchium palmifolium L. and Sisyrinchium vaginatum Spreng complexes, resulting in numerous misidentifications. The taxonomic confusion in the group may stem from various factors, emphasizing extensive morphological variations, leading to overlapping characteristics. We used morphometric approaches to better characterize the species belonging to two complexes, assess their variation and identify diagnostic traits for taxonomy enhancement. We assessed 16 quantitative traits for the S. palmifolium complex and 15 for the S. vaginatum complex, totaling 652 specimens recorded across 15 herbaria covering the entire species' distribution area. In the S. vaginatum complex, 66.5% of the variations were accounted for in the first two axes, while in the S. palmifolium complex, the first two axes explained 55.3%. Our findings revealed that both complexes exhibited many morphological variations, leading to a characteristic overlap. These characteristics may have arisen due to recent diversifications of the group and niche overlaps. Additionally, we identified some morphological characteristics that are useful for distinguishing species. Finally, we compiled a section gathering all useful characteristics for species delimitation within the group, aiming to facilitate non-experts in deciphering this species complex. [ABSTRACT FROM AUTHOR]

Passiflora, a genus with more than 400 species, exhibits a high diversity of floral and vegetative structures and a complex taxonomy, which includes 23 subgenera and many sections and series. To better understand Passiflora's variability and interspecific relationships, the phylogeny of 61 species, classified in 11 of 23 suggested subgenera, was investigated. Three molecular markers were used, the nuclear ribosomal internal transcribed spacers (nrITS), the plastid trnL-trnF spacer regions (~1000 bp), and the rps4 plastid gene (~570 bp). Three major clades were highly supported, independent of the marker and phylogenetic method used; one included the subgenera Distephana, Dysosmia, Dysosmioides, Passiflora, and Tacsonioides, a second, the subgenera Adopogyne, Decaloba, Murucuja, and Pseudomurucuja, and a third, the subgenus Astrophea. We call these the Passiflora, Decaloba, and Astrophea clades, respectively. The position of subgenus Deidamioides is undefined. The monophyly of Passiflora could not be statistically corroborated, and the relationships among the major clades and of these clades with the related genera remain unresolved. Our results indicate that a reevaluation of the monophyly of Passiflora and its infrageneric classification is necessary. Key words: ITS; Passiflora; Passifloraccae; phylogenetic analysis; rps4; trnL-trnF.

Evolutionary and ecological processes that influenced the assembly of the New World flora are best understood through investigation of spatio-temporal processes of specific lineages, but some groups still lack a historical overview. Here, we produced a well-sampled dated tree, reconstructed ancestral ranges and performed diversification analyses for Sisyrinchium (Iridaceae) to elucidate its evolution in the Americas. Eight molecular markers and samples representing its full geographical range and morphological diversity were used to estimate divergence times with a Bayesian relaxed clock with secondary calibrations. Ancestral range reconstruction under likelihood methods and diversification analyses were performed. Sisyrinchium originated in a broad range including the Andes and Mesoamerica in the Mid-Miocene. Diversification at high elevations occurred in the early diverging lineages, which feature the highest extinction rates. Increase in diversification rate was detected during the Pliocene/Pleistocene after the colonization of lower elevations. Later sympatric speciation in south-eastern Brazil was followed by movements to other regions, including a long-dispersal event to North America. Higher extinction rates were followed by movements to lower elevations, with periods of accelerated Andean orogeny and global temperature decrease. Our results indicate that palaeoclimate and changes in elevational range influenced diversification in Sisyrinchium. [ABSTRACT FROM AUTHOR]

The circumscription of the grass subtribe Calothecinae has undergone several changes since its description. Currently, it comprises Chascolytrum and the recently described genera Laegaardia and Paramochloa. Here we evaluate the circumscription of Calothecinae and the recently proposed infrageneric classification of Chascolytrum based on a phylogeny with more comprehensive taxon and molecular marker sampling than in previous studies. We sampled all Calothecinae genera, all but one Chascolytrum species, two South American Trisetum s.l., and representatives of the subtribes Agrostidinae, Brizinae, Echinopogoninae, Koeleriinae, Phalaridinae, and Torreyochloinae within Poaceae tribe Poeae. We performed Bayesian and Maximum Likelihood analyses of four plastid DNA regions (atpF‐atpH, matK, rps16 intron, and trnL‐trnF) and two nuclear ribosomal regions (ITS and ETS). Our results revealed that neither Calothecinae nor Chascolytrum is monophyletic, as currently recognized, because Trisetum brasiliense and Trisetum bulbosum are nested within Chascolytrum. We include these two Trisetum species in Calothecinae as incertae sedis. Laegaardia and Paramochloa form a clade that is sister to the Chascolytrum + Trisetum clade, and based on morphological characters, we transfer the former to the new subtribe Paramochloinae. Our Chascolytrum phylogeny is better resolved and supported than in previous studies, and based on these results, we divide Chascolytrum into nine genera, including two new ones: Boldrinia (gen. nov.), Calotheca, Chascolytrum, Erianthecium, Lombardochloa, Microbriza, Poidium, Rhombolytrum, and Rosengurttia (gen. nov.). We provide a key to Calothecinae genera, descriptions of the genera, nomenclatural information, and keys to species of each genus. In addition, six new combinations are proposed. [ABSTRACT FROM AUTHOR]

Abstract: The taxonomic delimitation of Vriesea is challenging because several diagnostic traits of the genus are shared with other genera in Tillandsioideae. The genus has no unique morphological features that distinguish it from other taxa. Earlier phylogenetic studies suggested a polyphyletic status of this genus, but taxon sampling was limited, and tests of congruence for morphological characters have not yet been performed. Here we used a total evidence approach and a more comprehensive Brazilian taxon sampling to help circumscribe Vriesea s.s. (the lineage that contains the type species). We concatenated morphological and molecular datasets for the first time to reconstruct phylogenetic hypotheses. We used 99 morphological characters and ~4 kb of plastid data (psbA‐trnH, trnK5′‐rps16, matK, trnL‐trnF) for 172 terminals, including nine genera of Tillandsioideae. We analysed datasets by parsimony analyses, with several weighting schemes considered for character‐state changes (equal weights and an implied weighting scheme that we used as a sensitivity analysis). The concatenated data resulted in a well‐resolved phylogenetic inference that provided strong evidence that the genus is not monophyletic as traditionally circumscribed. Given the congruence between morphological, molecular and geographical sources of data, we separated Vriesea into distinct lineages, and proposed a new circumscription that includes only species of Vriesea s.s. found in the Chacoan and Parana subregions. [ABSTRACT FROM AUTHOR]

A remarkable morphological similarity in natural populations of different groups of Sisyrinchium spp. ( Iridaceae) makes classification of some species difficult. The present paper focused on two morphological categories of S. sellowianum ( MC-I and MC-II) with distinct morphological traits. Morphological, cytogenetic, reproductive biology and genetic studies were performed, aiming to elucidate and better characterize such variation. The basic chromosome number established for the species was x = 9 and diploid and tetraploid populations were observed for MC-I, whereas MC-II showed only diploid populations. Different pollen morphologies were recognized in each morphological category. Based on pollination experiments, MC-I is out-crossing, whereas MC-II is selfing. The populations were highly differentiated ( F ST = 0.46, θB = 0.62). In MC-I, observed variation was greater within populations (69%) than among populations (31%), whereas in MC-II, 61% of the variation was among populations and 39% within populations. This study evidenced that the two morphological categories correspond to distinct and reproductively isolated species and that floral traits reflect their breeding system, with allogamous plants in MC-I and autogamous in MC-II. Furthermore, MC-II is unveiled as S. platycaule, a neglected taxon of Sisyrinchium in Brazil. The tools applied in this study were substantially able to check the identity of the two morphological categories as two different species and present the variation encountered in the taxa. [ABSTRACT FROM AUTHOR]