Infrageneric Categories Research Articles

Evolution of vegetative morphoanatomical characters in Pabstiella (Pleurothallidinae: Orchidaceae)

The subtribe Pleurothallidinae encompasses approximately 48 genera, with Pabstiella standing out due to its 133 species, many of which are found in Brazil's Atlantic Forest. Molecular data strongly support the genus and its ten sections. However, only a few species have been anatomically described, and a comprehensive characterization of the genus for comparative purposes is still needed. Our study aimed to examine the main vegetative morphoanatomical characters of the root, stem, and leaves, and analyze their evolution based on the phylogeny of the genus. We analysed root, stem, and leaf samples from 57 species using light and scanning electron microscopy. We selected 35 characters and mapped them onto the molecular phylogeny. Pabstiella exhibits homogeneous leaf anatomy, with aquiferous tissue on both sides and chlorophyllous parenchyma in the middle, aligned with vascular bundles. The ramicaul anatomy displays a simple epidermis with primary or secondary walls, a simple to stratified hypodermis, a parenchymatous or aerenchymatous cortex, and a sheath of sclerenchyma surrounding the vascular bundles. The roots endovelamen cells are larger than those in the epivelamen, reticulated tilosomes of varying morphotypes, and giant cells in the cortex. Despite the common occurrence of homoplasy among vegetative traits, particularly in the leaves, our analyses revealed several synapomorphies for the genus. These include the presence of giant cells in the root cortex, endovelamen cells larger than those of the epivelamen, a specific distribution pattern of tilosomes, and 2–3 layers of aquifer tissue on the adaxial face of the leaf. Additionally, for the Pabstiella section, a lignified stem epidermis wall is a synapomorphic character state. Our findings demonstrate that vegetative morpho-anatomy is a useful diagnostic character for generic and infrageneric categories within the genus. When analysed from a phylogenetic perspective, it contributes to our comparative understanding of the genus.

A taxonomic account of Myrcia (Myrtaceae) at the sites of the Biological Dynamics of Forest Fragments Project, Amazonas, Brazil

Abstract Myrcia is the sole genus of the Myrciinae, one of the nine subtribes of Myrteae (Myrtaceae). The Amazon forest holds about one-quarter of the Brazilian species of Myrcia, but the genus is still understudied in this whole region. In this context, this study presents a floristic survey of Myrcia in the permanent plots of the Biological Dynamics of Forest Fragments Project (BDFFP), in Amazonas state, Brazil. The genus is represented by 36 species in the study area, comprehending 32% of its total richness in the Brazilian Amazon forest, with 19 of them endemic to this domain. Myrcia neospeciosa is reported as a new occurrence for Amazonas state and M. grandis is recorded for the first time from upland terra firme forests on clayish soils. Myrcia cuspidata, a species with calyptrate flowers, is classified under Myrcia sect. Aulomyrcia, representing the second taxon of the genus with this feature removed from Myrcia sect. Calyptranthes. Finally, morphological aspects of the infra-generic categories of Myrcia are reported more overlapping than previously thought. A map containing the location of the study area, an identification key, descriptions, comments, and figures are provided.

A new infrageneric classification of the pantropical genusChamaecrista(Fabaceae: Caesalpinioideae) based on a comprehensive molecular phylogenetic analysis and morphology

AbstractChamaecrista with > 330 species, six sections, three subsections and 39 series has had a long and complex taxonomic history. The genus is monophyletic, but most of its traditional infrageneric categories are not. To test the monophyly of sections, subsections and series of Chamaecrista, we used two molecular phylogenetic approaches. The first (Broad) based on two DNA regions (ITS and trnL-F) includes a comprehensive sampling of Chamaecrista spp. and infrageneric taxa. The second (Multilocus) is based on four molecular regions (ITS, ETS, trnL-F and trnE-T) for a smaller but representative sampling. We performed ancestral character reconstructions to identify morphological characters that could serve as synapomorphies for major clades. Both molecular approaches support Chamaecrista and sections Apoucouita, Grimaldia and Xerocalyx as monophyletic, but sections Chamaecrista, Caliciopsis and Absus and most of the series are not monophyletic. The four main clades recovered are all characterized by a combination of morphological characters: a clade of tree species with cauliflorous inflorescences (including species of section Apoucouita); a mostly Brazilian campo rupestre clade (including all species of subsections Adenophyllum, Baseophyllum and Otophyllum); a clade of mostly herbaceous/shrubby species with solitary flowers or fascicles (including sections Chamaecrista, Caliciopsis and Xerocalyx and extra-American species) and a clade (with three main subclades) of species with viscous indumentum (including section Grimaldia and section Absus subsection Absus). We propose a new infrageneric classification for Chamaecrista supported by molecular phylogenetic analyses and morphology, recognizing the four main clades as sections Apoucouita, Baseophyllum, Chamaecrista and Absus, the last with three subsections (Absus, Viscosa and Zygophyllum), but we do not recognize any previously circumscribed series. Our taxonomic treatment includes descriptions of and a key to the newly defined infrageneric taxa and an updated species list for the genus under the new classification.

A taxonomic account of Myrcia (Myrtaceae) at the sites of the Biological Dynamics of Forest Fragments Project, Amazonas, Brazil

Abstract Myrcia is the sole genus of the Myrciinae, one of the nine subtribes of Myrteae (Myrtaceae). The Amazon forest holds about one-quarter of the Brazilian species of Myrcia, but the genus is still understudied in this whole region. In this context, this study presents a floristic survey of Myrcia in the permanent plots of the Biological Dynamics of Forest Fragments Project (BDFFP), in Amazonas state, Brazil. The genus is represented by 36 species in the study area, comprehending 32% of its total richness in the Brazilian Amazon forest, with 19 of them endemic to this domain. Myrcia neospeciosa is reported as a new occurrence for Amazonas state and M. grandis is recorded for the first time from upland terra firme forests on clayish soils. Myrcia cuspidata, a species with calyptrate flowers, is classified under Myrcia sect. Aulomyrcia, representing the second taxon of the genus with this feature removed from Myrcia sect. Calyptranthes. Finally, morphological aspects of the infra-generic categories of Myrcia are reported more overlapping than previously thought. A map containing the location of the study area, an identification key, descriptions, comments, and figures are provided.

Molecular Phylogeny of Axonopus (Poaceae, Panicoideae, Paspaleae): Monophyly, Synapomorphies, and Taxonomic Implications for Infrageneric Classification and Species Complexes

Axonopus P. Beauv. comprises nearly 90, mostly New World, species characterized by having spikelets with the inverse position (i.e., the backs of the upper glume and the upper lemma turned away from the rachis). The genus has been divided into four sections, five series, and three subseries, based exclusively on morphological features. Previous phylogenetic analyses based on a limited sampling of species showed Axonopus to be a monophyletic genus. In this study we increased the number of species sampled (46 species in the combined tree) and sequenced four DNA regions (external transcribed spacer [ETS], internal transcribed spacer [ITS], trnL-F, and ndhF). We tested the monophyly of Axonopus and its traditional infrageneric categories using parsimony, likelihood, and Bayesian inference. Additionally, we performed ancestral character state reconstructions of 45 morphological characters to infer autapomorphies of the species and synapomorphies for the genus and clades. Our findings confirmed Axonopus as a monophyletic genus only when Centrochloa Swallen and Ophiochloa Filg., Davidse & Zuloaga are included within it. Our analyses also showed that, with the exception of section Lappagopsis, infrageneric categories from previous classifications of the genus are artificial. Twenty-one morphological character states were identified as potential autapomorphies; two were reconstructed as potential synapomorphies for Axonopus, whereas 12 were reconstructed as potential synapomorphies for specific clades within the genus. Further molecular analyses, including sequencing of unlinked nuclear genes, are needed in order to reach a robust phylogenetic classification of the genus.

Phylogenetics ofPaepalanthus(Eriocaulaceae), a diverse Neotropical monocot lineage

AbstractPaepalanthus is a diverse monocot genus with remarkable diversity distributed in the Neotropical highlands of South America. The genus comprises 410 species arranged in subgenera, sections, subsections and series. Added to this complex classification, Paepalanthus shows considerable morphological heterogeneity and includes three other genera in it, Actinocephalus (Körn.) Sano, Lachnocaulon Kunth and Tonina Aubl. A broadly sampled phylogenetic inference for the genus is still missing, precluding a better understanding of its delimitation and further studies in the group. Here we present the most comprehensive phylogenetic study for Paepalanthus to date, as well as morphological survey of characters that delimit the main lineages found. We assembled a morphologically and geographically representative sampling of Paepalanthus and associated genera comprising 356 accessions in a combined dataset of plastid (trnL-F, psbA-trnH) and nuclear (ITS, ETS) regions. Bayesian inference and maximum likelihood methods were used for phylogenetic reconstruction. We found that Paepalanthus and 16 of its 28 infrageneric categories are not monophyletic, as well as the closely related genus Actinocephalus. Thirty-six well-supported clades are recognized. Morphological characters show high levels of homoplasy, and concepts traditionally used in the classification of Paepalanthus were found to be inconsistent. We confirmed that Paepalanthus as currently circumscribed is not monophyletic and revealed several new relationships in Eriocaulaceae. To make Paepalanthus monophyletic, the genus must be re-circumscribed. These results also provide a foundation for future investigations of the diversification and evolution of flora of the Neotropical highlands of South America.

<p><strong>Phylogenetic relationships of <em>Echeveria </em>(Crassulaceae) and related genera from Mexico, based on three DNA barcoding loci</strong></p>

Mexico is considered as diversification and endemism center of the genus Echeveria. Previous tree inference studies have shown the genus to be non-monophyletic in relation to other genera, but sampling for Echeveria has been poor, and has not allowed to understand the relationships within the genus. In this work, Bayesian and maximum likelihood phylogenetic analysis were performed, using a combined standard DNA barcoding loci matrix (rbcL, matK and ITS2) and GenBank ITS2 accessions for Graptopetalum, some Sedum and few Echeveria taxa. The selection of taxa encompasses all current infrageneric categories of the genus Echeveria, as well as species from genera previously associated with it. The inferred consensus trees suggested that Echeveria is paraphyletic. Instead, four main clades were retrieved within the “Echeveria group”: Clade I includes exclusively Pachyphytum species. Clade II is formed by the majority of series Urbiniae; Clade III encompasses series Chloranthae, Ciliatae, Echeveria, Mucronatae, Nudae, Racemosae, Thyrsiflorae, Pachyphytum cuicatecananum and Thompsonella; Clade IV contains series Angulatae, Gibbiflorae, Occidentales, Pruinosae, Secundae, some Urbiniae species, Valvatae. genera Cremnophila, Graptopetalum and Reidmorania. Pachyphytum and Thompsonella were retrieved as monophyletic groups, but the first outside Echeveria while the latter inside. Results of our study suggest that Echeveria and the Echeveria Group require a redefinition.

Phylogeny and divergence time estimation of Chamaecrista ser. Rigidulae (Leguminosae: Caesalpinioideae)

Chamaecrista is a monophyletic genus, but most of its infrageneric categories have been shown to be paraphyletic, including series Rigidulae which currently comprises 30 species, all endemic to Brazil and most occurring in the cerrado vegetation of the central highlands of the country. This molecular phylogenetic study tests the monophyly of C. ser. Rigidulae based on a broad sampling, considers its relationship with members of C. sect. Absus subsect. Absus, and estimates its divergence time in relation to the age of the genus. For that, individual and combined analyses were performed by the parsimony and Bayesian methods using chloroplast (trnL‐F) and nuclear (ITS1‐5.8S‐ITS2) markers and a matrix containing 75 taxa of Chamaecrista (29 belonging to series Rigidulae), 6 of Senna and 1 of Cassia. The analyses showed that series Rigidulae, as traditionally circumscribed, is polyphyletic. When C. brachyblepharis and C. ciliolata are excluded and C. botryoides and C. sincorana included, the series is resolved as monophyletic, comprising 30 species here designated as the Rigidulae clade. This clade is further subdivided into two geographically and genetically structured subclades, the first containing 23 species, mostly from the highlands of Goiás State, and the second with 6 species from the Espinhaço Range, running north to south through central Bahia and Minas Gerais States. Divergence time analyses suggest that the Rigidulae clade originated about 5 million years ago. The recent radiation of the series repeats that seen in other species‐rich genera in the Cerrado Biome, thus corroborating previous hypotheses about the recent age of the biome. The Rigidulae clade, as here circumscribed, has the following morphological synapomorphies: asymmetric flowers with their posterior petals similar to a typical papilionoid standard petal, and leaflets divaricate along the leaf rachis.

Phylogeny and staminal evolution of Salvia (Lamiaceae, Nepetoideae) in East Asia.

Salvia is the largest genus within Lamiaceae, with about 980 species currently recognized. East Asia, with approx. 100 species, is one of the three major biodiversity centres of Salvia. However, relationships within this lineage remain unclear, and the staminal lever mechanism, which may represent a key innovation within the genus, has been understudied. By using six genetic markers and nearly comprehensive taxon sampling, this study attempts to elucidate relationships and examine evolutionary trends of staminal development within the East Asia (EA) Salvia clade. Ninety-one taxa of EA Salvia were sampled and 34 taxa representing all other major lineages of Salvia were included for analysis. Two nuclear [internal transcribed spacer (ITS) and external transcribed spacer (ETS)] and four chloroplast (psbA-trnH, ycf1-rps15, trnL-trnF and rbcL) DNA markers were used for phylogenetic analysis employing maximum parsimony (MP), maximum likelihood (ML) and BEAST, with the latter also used to estimate divergence times. All Salvia species native to East Asia form a clade, and eight major subclades (A-G) were recognized. Subclade A, comprising two limestone endemics (S. sonchifolia and S. petrophila), is sister to the remainder of EA Salvia. Six distinct stamen types were observed within the EA clade. Stamen type A, with two fully fertile posterior thecae, only occurs in S. sonchifolia and may represent the ancestral stamen type within EA Salvia. Divergence time estimates showed that the crown of EA Salvia began to diversify approx. 17.4 million years ago. This study supports the adoption of a broadly defined Salvia and treats EA Salvia as a subgenus, Glutinaria, recognizing eight sections within this subgenus. Stamen type A is ostensibly plesiomorphic within EA Salvia, and the other five types may have been derived from it. Staminal morphology has evolved in parallel within the EA Salvia, and staminal structure alone is inadequate to delimit infrageneric categories.

Historia de Passiflora Supersec. Tacsonia (Passi oraceae): un acercamiento taxonómico

Introduction : Genus Passi ora (Passi oraceae) brings together the largest number of wild, edible and cultivated species of importance in national and international markets for consumption as fresh or processed fruit. Species Tacsonia ( Passi or a), generally recognized as curubas, have been extensively studied since the time of Linnaeus f. (1781) to the present, but with di erent taxonomic treatments that have generated combinations since gender to its infrageneric changes Passi ora . Objective : Knowing the taxonomic history of Tacsonia , their changes over time, the discovery of new species, synonyms, basonimos, new status and classi cation systems used in each period to its current situation. Results : Thus, generic changes correspond to Tacsonia , Rathea and Poggendor a to include the 65 species currently belong to the sus - persection Tacsonia , morphological, phylogenetic, bioclimatic and geographic taxon supports. Followed infrageneric knowledge of groups and species that formed according to the taxonomic work is covered, which It supports the monophyly of the supersection. In addition, each species and variety is mentioned since the publication of the type and its trayectory through the infrageneric categories. Conclusion : Knowle - dge of the taxonomic history of the species Tacsonia provides a solid basis to support taxonomic work and morphological characterization, molecular, cytogenetic and palynological establish the relationships infrasuperseccion level, which still morphological, genetic and biogeographic data are shown controversial.

Morphological Phylogenetic Analysis of Two Early-Diverging Genera of Bromelioideae (Bromeliaceae)

Abstract Bromelia includes 66 species, grouped in three subgenera: Bromelia, Distiacanthus and Karatas. The genus is one of the earlier divergent groups within Bromelioideae, a subfamily with innumerable problems of generic delimitation. Considering that few phylogenetic studies have included more than one species of Bromelia, the objectives of this study were to carry out a phylogenetic analysis for the genus, seeking to evaluate its monophyly as well as its subgenera, and to better understand the interspecific evolutionary relationships within the genus and the intergeneric relationships within Bromelioideae. Also included in the analysis were the two species of Fernseea, a genus originally described from a species placed in Bromelia. The phylogenetic analysis was conducted with combined micro- and macromorphological data, including 39 taxa with 116 characters. As in other studies on Bromeliaceae, the clades have low statistical support and many questions regarding the relationships of the groups remain. The circumscription of Bromelia is still uncertain, due to the position of B. irwinii; Fernseea seems to emerge within this genus, as the marority-rule consensus suggests, and the infrageneric categories are debatable because they do not constitute monophyletic groups. However, Bromelia seems to be paraphyletic and, without B. irwinii, the genus can be considered monophyletic. Beginning with the premise that the most recent common ancestor of Bromelioideae appeared first in the southern Andes, Bromelia and Fernseea seems to have dispersed along three biogeographical routes. The present work is an important contribution to understand the evolution and biogeography of the Bromelioideae.

Reaching a compromise between conflicting nuclear and plastid phylogenetic trees: a new classification for the genus Cattleya (Epidendreae; Epidendroideae; Orchidaceae)

A new classification for the 114 species Cattleya is proposed, based on and compatible with previously published nuclear, plastid and combined phylogenetic trees. Cattleya is divided into four subgenera, three sections and five series. A key to the infrageneric categories and a table listing all species and their placement is presented.

Taxonomic survey of Paepalanthus section Diphyomene (Eriocaulaceae)

Paepalanthus is the largest genus in Eriocaulaceae, comprising about 400 species distributed mainly throughout the Neotropics. Through phylogenetic studies it has been demonstrated that the genus is polyphyletic, although many of its infrageneric categories are monophyletic. In an attempt to clarify the nomenclature and classification of Paepalanthus, we present a taxonomic survey of Paepalanthus section Diphyomene. This group consists of 10 species restricted to South America and is defined by inflorescences being arranged in the form of a tribotryum with terminal dibotryum, a terminal basic unit and pherophylls subtending the lateral dibotrya. Further important distinguishing characteristics are dimerous flowers, pistillate flowers with dolabriform sepals, bifid stigmatic branches and absent staminodes, and staminate flowers with an elongated anthophore. We hereby propose 19 new synonyms, six lectotypifications, one new status, one neotypification and one epitypification.

Phylogenetic relationships in Kumanoa (Batrachospermales, Rhodophyta) species in Brazil with the proposal of Kumanoa amazonensis sp. nov.

Necchi O. Jr., Vis M.L. and Oliveira M.C. 2010. Phylogenetic relationships in Kumanoa (Batrachospermales, Rhodophyta) species in Brazil with the proposal of Kumanoa amazonensis sp. nov. Phycologia 49: 97–103. DOI: 10.2216/09-24.1This study evaluated the species-level taxonomy and phylogenetic relationship among Kumanoa species from Brazil with other regions of the world based on the plastid-encoded RUBISCO large subunit gene (rbcL). Partial rbcL sequences were obtained for 11 Kumanoa specimens. Eight species are recognised from Brazil on the basis of molecular and morphological data: seven previously described (K. abilii, K. ambigua, K. breviarticulata, K. cipoensis, K. equisetoidea, K. globospora and K. procarpa) and a new species here proposed (K. amazonensis sp. nov. Necchi & Vis). The new species has reduced and dense whorls but differs from the two closest related species in lacking secondary fascicles. Previously proposed infrageneric categories were not supported by the molecular data. Species described and endemic (K. breviarticulata, K. cipoensis, K. equisetoidea and K. procarpa) to Brazil are not grouped together but are variously related to other species from North America, Europe and Australasia. With the species recognised in this study using molecular and morphological data and those previously distinguished by morphology, 13 species of Kumanoa are currently documented from Brazil.

Comparative floral ontogeny in Adesmia (Leguminosae: Papilionoideae: Dalbergieae)

Floral organogenesis of six Brazilian species of Adesmia DC. was studied by scanning electron microscopy. Considering the number of species, this is the most comprehensive organogenetic study of a genus conducted. A unidirectional sepal formation from the adaxial towards the abaxial side of the floral meristem is shown for the first time in the subfamily Papilionoideae. This pattern was found in all studied taxa except for A. latifolia in which the five sepal primordia are formed simultaneously. The present study suggests that the ontogenetic floral differences among Adesmia species may be useful in a re-evaluation of infrageneric categories and for future systematic analyses.

A synopsis of Ipomoea (Convolvulaceae) in the Americas

SummaryAustin, D. F. & Huáman, Z.: A synopsis of Ipomoea (Convolvulaceae) in the Americas. – Taxon 45: 3‐38. 1996. – ISSN 0040‐0262.A total of 339 taxa (327 species, five varieties, five subspecies) currently are recognized in the Americas, with the caveat that additional taxa exist that are unstudied and undescribed. Those species recognized are placed, when possible, in infrageneric categories. Known distributions are given for each taxon. Synonyms and names of uncertain application are listed.

<strong>Campylopus, a modern and successful genus !?</strong>

Campylopus with nearly 200 revised species is one of the largest genera of mosses in the world and has extremely broad geographical, altitudinal and ecological ranges. Factors to be considered for the rich speciation are 1) the enormous anatomical plasticity of the structure of the costa, 2) the ability for vegetative propagation utilizing different methods, and 3) the special twist mechanism of the cygneous setae. Phytogeographical interpretations of present ranges of species of Campylopus lead to the conclusion that this genus is of Gondwanalandic origin. Most of the species seem to be cool temperate in origin. They have adapted to dry habitats in the Mesozoic and invaded the tropical mountains during the Tertiary, accompanied by rich speciation. This is supported by the physiology of these species. According to preliminary gas exchange measurements, tropical montane species do not differ from temperate species, and are not able to stand climatic conditions of the tropical lowland rainforests; a relatively young habitat for bryophytes. A cladistic analysis of the infrageneric categories of Campylopus using phytogeographical evaluations of apomorphic character states shows that the section Homalocarpus seems to be the most primitive and the subgenera Campylopidulum and Thysanomitrion the most derived.

Infrageneric classification and species composition of the anole genera, Anolis, Ctenonotus, Dactyloa, Norops and Semiurus (Sauria: Iguanidae)

AbstractAll valid species of Anolis, Ctenonotus, Dactyloa, Norops and Semiurus are listed by genus and where possible by the infrageneric categories (from most to least inclusive): series, subseries and species groups. An alphabetical index cross-referencing the species names to genus and series is also included.

A Synopsis of North American Asters: The Subgenera, Sections and Subsections of Aster and Lasallea

Traditional treatments of Aster were found unsatisfactory in predicting cytological and morphological characteristics of members of various subgenera, sections and subsections of different authors. A realignment of species into these infrageneric categories is presented and is based on sets of shared morphological characteristics of roots or rhizomes, leaves, and phyllaries. Eight subgenera are recognised in Aster. Subgenus Aster is divided into five sections on morphological characteristics: three have X = 9, one has X = 8 and one has X = 7. Subgenus Aster section Dumosi has been redefined and contains all the X = 8 species. Ten X = 5 species and one X = 4 species previously classified in up to six sections of subgenus Aster were found to be morphologically and cytologically related to each other, but unrelated to the other species of Aster. These eleven species have been assigned to the genus Lasallea sensu Semple & Brouillet. Lasallea has been divided in sections and subsections with new combinations presented in this paper.

A SYNOPSIS OF NORTH AMERICAN ASTERS: THE SUBGENERA, SECTIONS AND SUBSECTIONS OF ASTER AND LASALLEA

Traditional treatments of Aster were found unsatisfactory in predicting cytological and morphological characteristics of members of various subgenera, sections and subsections of different authors. A realignment of species into these infrageneric categories is presented and is based on sets of shared morphological characteristics of roots or rhizomes, leaves, and phyllaries. Eight subgenera are recognised in Aster. Subgenus Aster is divided into five sections on morphological characteristics: three have X = 9, one has X = 8 and one has X = 7. Subgenus Aster section Dumosi has been redefined and contains all the X = 8 species. Ten X = 5 species and one X = 4 species previously classified in up to six sections of subgenus Aster were found to be morphologically and cytologically related to each other, but unrelated to the other species of Aster. These eleven species have been assigned to the genus Lasallea sensu Semple & Brouillet. Lasallea has been divided in sections and subsections with new combinations presented in this paper.