In its broadest sense, Scirpus consists of a heterogeneous assemblage of up to 250 species, but modern circumscriptions suggest that only 40–50 species are part of the genus. Despite a narrower definition of the genus, atypical species continue to be segregated from Scirpus with a common pattern being the removal of Southern Hemisphere taxa to other genera and tribes. In South America, the morphology of remaining Scirpus species also suggests that they are not closely related to Scirpus s.str., but most of these taxa are only known from their types, making a detailed analysis of their generic affinities difficult. One notable exception is Scirpus asper, a species that is relatively common in the mountains and adjacent lowlands of Peru south to Argentina. Although this species possesses features used in the circumscription of Scirpus, such as cauline leaves, flat leaf blades and anthelate inflorescences, it is known to differ from Scirpus s.str. by its Schoenus‐type embryo, and most of its presumed allies are now placed in different genera (e.g., Scirpus analecti ≡ Cypringlea analecta; Scirpus giganteus ≡ Androtrichum giganteum). In this study, we use DNA sequence data from the plastid (matK, ndhF) and nuclear (ETS‐1f) genomes to demonstrate that Scirpus asper is not closely related to Scirpus s.str., but sister to Phylloscirpus within the predominantly South American Zameioscirpus clade (Amphiscirpus, Phylloscirpus, Zameioscirpus). When combined with morphological, anatomical and embryological data, results indicate that S. asper is best treated as the sole species of a new monotypic genus, Rhodoscirpus. The implications of these results on the taxonomy of tribe Scirpeae are discussed.

Pennisetum (80–140 species) and Cenchrus (16–22 species) are closely related genera of Paniceae, both distributed in tropical and sub‐tropical regions. The distinction between Pennisetum and Cenchrus is not clearly defined, and currently no comprehensive taxonomic treatment is available for either genus. Chloroplast DNA sequence data (rpl16, trnL‐F region) were analyzed to test their monophyly, species relationships, and infrageneric classifications. Phylogenetic analyses of individual genomic regions, and a combined dataset, including indel‐coded information, were performed under parsimony and Bayesian inference. Selected geographical, chromosomal and morphological characters were mapped onto the phylogeny to investigate evolutionary trends. Our results support a monophyletic bristle clade and the close relationship between Pennisetum and Cenchrus. Excluding Pennisetum lanatum, Pennisetum is paraphyletic because Cenchrus is nested within it. Sections Pennisetum and Gymnotrix are polyphyletic. Our molecular phylogenetic results show a close relationship among the domesticated species P. glaucum, P. purpureum, P. squamulatum, P. nervosum, and P. sieberianum, suggesting the potential use of these species in crop improvement. The Pennisetum‐Cenchrus clade shows an independent reduction (x = 5, 7, 8) or duplication (x = 17) of the basic chromosome number from the ancestral x = 9. American Pennisetum and Cenchrus species appear to have originated from Old World species more than once. A core group of American species of Cenchrus with a basic chromosome number of x = 17 and retrorsely barbed bristles could be restricted to Cenchrus s. str.

Full plastome sequences for land plants have become readily accessible thanks to the development of Next Generation Sequencing (NGS) techniques and powerful bioinformatic tools. Despite this vast amount of genomic data, some lineages remain understudied. Full plastome sequences from the highly diverse (>1,500 spp.) subfamily Tillandsioideae (Bromeliaceae, Poales) have been published for only three (i.e., Guzmania, Tillandsia, and Vriesea) out of 22 currently recognized genera. Here, we focus on core Tillandsioideae, a clade within subfamily Tillandsioideae, and explore the contribution of individual plastid markers and data categories to inform deep divergences of a plastome phylogeny. We generated 37 high quality plastome assemblies and performed a comparative analysis in terms of plastome structure, size, gene content and order, GC content, as well as number and type of repeat motifs. Using the obtained phylogenetic context, we reconstructed the evolution of these plastome attributes and assessed if significant shifts on the evolutionary traits’ rates have occurred in the evolution of the core Tillandsioideae. Our results agree with previously published phylogenetic hypotheses based on plastid data, providing stronger statistical support for some recalcitrant nodes. However, phylogenetic discordance with previously published nuclear marker-based hypotheses was found. Several plastid markers that have been consistently used to address phylogenetic relationships within Tillandsioideae were highly informative for the retrieved plastome phylogeny and further loci are here identified as promising additional markers for future studies. New lineage-specific plastome rearrangements were found to support recently adopted taxonomic groups, including large inversions, as well as expansions and contractions of the inverted repeats. Evolutionary trait rate shifts associated with changes in size and GC content of the plastome regions were found across the phylogeny of core Tillandsioideae.

The Neotropical genus Tillandsia (Bromeliaceae) is an excellent model system for macroevolutionary and biogeographic studies owing to its remarkable species diversity (ca. 650 spp.) and varied morphological and ecological adaptations to epiphytic and saxicolous habitats. Recent phylogenetic studies have greatly improved our knowledge about generic limits and infrageneric classification of Tillandsia. These studies have identified two clades of Tillandsia characterized by a distinct geographic distribution: (i) a North and Central American clade that includes species from subgenus Tillandsia; and (ii) a central South American clade containing species from subgenera Aerobia, Anoplophytum, Diaphoranthema, and Phytarrhiza. Our study aimed to determine the size, composition, and potential geographic structure of these two clades within the context of a global phylogeny of Tillandsioideae. With the addition of 100 newly sequenced species to previous studies to cover the now ca. 30% of the known species diversity of Tillandsia, our analyses found both clades to be strongly supported, and revealed that their species richness is much greater than previously known. Ancestral area estimation suggests that most of the diversification of the first of these clades took place in North and Central America, whereas within the second, most of the migratory events occurred from the Andes to the Brazilian shield.

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Notas taxonómicas y de distribución de Carex (Cyperaceae) en el Neotrópico. Presentamos datos relevantes acerca de la taxonomía y distribución de 20 especies del género Carex en el Neotrópico(de la region Caribe a la Patagonia). Aportamos un total de 19 registros nuevos, dos de ellos para especies hasta el momento no registradas para Sudamérica, diez especies citadas como novedad para diferentes países y siete especies aquí reportadas como novedades regionales en Argentina, Bolivia y Chile. Lectotipificamos de nueve nombres de especies (C. brehmeri, C. catharinensis, C. ecuadorica, C. firmicaulis, C. fuscula, C. mandoniana, C. phleoides, C. polysticha y C. subantarctica) y epitipificamos uno de ellos (C. fuscula). Finalmente, proponemos a Carex koyamae como nuevo sinónimo de Carex phleoides.

Tillandsia uruguayensis (Bromeliaceae), a new xeromorphic and epilithic species from northern Uruguay, is described. The species belongs to the subgenus Aerobia and is morphologically related to T. lorentziana. This work provides a detailed morphological description, as well as information on distribution, habitat, phenology, and conservation status. Additionally, the main differences between T. uruguayensis and other morphologically similar species are discussed. Illustrations, images and a distribution map are supplied.

Tillandsia subgenera Diaphoranthema and Phytarrhiza s.s. are closely related epiphytic and epilithic plants adapted to xeric habitats in the Americas. Several studies suggested that subgenus Diaphoranthema and the xerophytic species of subgenus Phytarrhiza should not be segregated into different subgenera. In recent phylogenetic analyses of Tillandsioideae, subgenus Phytarrhiza s.l. is revealed as highly polyphyletic, showing a xerophytic lineage closely related to subgenus Diaphoranthema. Moreover, the evolution of neotenic traits, a selfing breeding system and polyembryony have yet to be fully investigated in a phylogenetic context. Infrageneric classifications and phylogenetic relationships were inferred using the plastid matK-trnK and nuclear ETS markers and morphology. Phylogenetic analyses of individual and combined molecular data sets were performed under parsimony and Bayesian inference. Our results confirm subgenus Diaphoranthema as monophyletic if three xeric species of subgenus Phytarrhiza are included. In subgenus Diaphoranthema, aggregates Loliacea and Rectangula were recovered as monophyletic, whereas Myosura was paraphyletic and Caliginosa, Capillaris and Recurvata were polyphyletic. Alternative groupings and morphological trends are discussed. Analysis of morphological characters associated with heterochrony indicates that neoteny may not be the only paedomorphic process in the evolution of this group. Furthermore, paedomorphosis would occur in some vegetative structures, inflorescences and flowers, whereas some fruit and seed traits could be modified by peramorphosis.