Generic Delimitation Research Articles

Pollen morphology and its systematic value to southern South American species of Lepidaploa (Vernonieae: Asteraceae)

Abstract Palynological data have been used in Vernonieae for generic and specific delimitations, particularly in the Lepidaploinae subtribe. For this reason, pollen studies in the genus Lepidaploa are important to solve taxonomic conflicts. We characterized 23 species of Lepidaploa searching for morphological differences among themselves. We then compared the data obtained with other genera of the Lepidaploinae. The results show that the species have pollen type “C” (with polar lacuna) or “G” (without polar lacuna), oblate-spheroidal, subprolate or prolate-spheroidal, 3-colporate and equinolophate. The pollen types and shape of pollen grain are taxonomically useful. Pollen morphology is useful to distinguish species and genera of Lepidaploinae. Together with macromorphological data it is possible to delimit Lepidaploa and the species studied here.

<p><strong><em>Tocoyena longilobata</em></strong><strong>, a replacement name for <em>Posoqueria speciosa</em> (Gardenieae, Rubiaceae)</strong></p>

Aublet (1775) described Posoqueria Aublet (1775: 133, tab. 51) and differentiated it from Tocoyena Aublet (1775: 131, tab. 50) by the number of locules of the ovary (unilocular vs. bilocular, respectively) and seed shape (angulate vs. subspherical, respectively). However, in subsequent studies, L.C.M.Richard (1792) and Lamarck (1793) published under Tocoyena certain species that morphologically matched the generic concept of Posoqueria, causing an historical confusion concerning their generic delimitation. Achille Richard (1830), in his Mémoire sur la famille des Rubiacées, synonymized Posoqueria under Tocoyena, a generic delimitation not widely adopted by subsequent authors. For example, Schumann (1889) in Flora Brasiliensis treated Posoqueria and Tocoyena as distinct genera.

<p><strong>The phylogenetic position and taxonomic status of the Southeast and South Asian bamboo genera <em>Neohouzeaua</em> and <em>Ochlandra</em> (Poaceae: Bambusoideae) </strong></p>

Among the tropical woody bamboos, the Melocanninae is one of the most clearly recognized subtribes morphologically and has also been consistently well delimited in molecular phylogenetic work. The relationships among those genera in this subtribe, however, have been contentious because of poorly understood generic delimitations, in part due to poor specimen material or insufficiently assessed morphological traits, sometimes exacerbated by poorly accessible provenances. We address the phylogenetic and taxonomic status of two groups which together include the largest number of species in this subtribe: the Neohouzeaua-Schizostachyum complex, distributed from India to South China, Southeast Asia and southwest Pacific, and the endemic Indian genus Ochlandra. Three Neohouzeaua species (including the generic type), 12 Schizostachyum species (including the generic type and several species of uncertain placement), together with five species of Ochlandra and representatives of Cephalostachyum, Melocanna and Pseudostachyum were assessed in a molecular phylogenetic analysis together with members of other well-distinguished subtribes. Members of Neohouzeaua and Schizostachyum align into two main groups that were not completely well-supported statistically but which members possess mostly reflexed culm leaf blades, or mostly erect culm leaf blades. Other characters which provide obvious differences between taxa, such as the number of flowers in a pseudospikelet, fusion of filaments into a staminal tube, and presence of lodicules, were inconsistent between these groups. Neohouzeaua and Schizostachyum cannot be clearly distinguished in either morphological or molecular terms, and thus are united under the latter name, which takes precedence. In reviewing names in Neohouzeaua and their basionyms, several lectotypifications are designated. Three new combinations in Schizostachyum are proposed. On the other hand, Ochlandra forms a distinct clade and its monophyly is demonstrated, supported by clear morphological characters.

Combination of Sanger and target-enrichment markers supports revised generic delimitation in the problematic ‘Urera clade’ of the nettle family (Urticaceae)

Urera Gaudich, s.l. is a pantropical genus comprising c. 35 species of trees, shrubs, and vines. It has a long history of taxonomic uncertainty, and is repeatedly recovered as polyphyletic within a poorly resolved complex of genera in the Urticeae tribe of the nettle family (Urticaceae). To provide generic delimitations concordant with evolutionary history, we use increased taxonomic and genomic sampling to investigate phylogenetic relationships among Urera and associated genera. A cost-effective two-tier genome-sampling approach provides good phylogenetic resolution by using (i) a taxon-dense sample of Sanger sequence data from two barcoding regions to recover clades of putative generic rank, and (ii) a genome-dense sample of target-enrichment data for a subset of representative species from each well-supported clade to resolve relationships among them. The results confirm the polyphyly of Urera s.l. with respect to the morphologically distinct genera Obetia, Poikilospermum and Touchardia. Afrotropic members of Urera s.l. are recovered in a clade sister to the xerophytic African shrubs Obetia; and Hawaiian ones with Touchardia, also from Hawaii. Combined with distinctive morphological differences between Neotropical and African members of Urera s.l., these results lead us to resurrect the previously synonymised name Scepocarpus Wedd. for the latter. The new species epiphet Touchardia oahuensis T.Wells & A.K. Monro is offered as a replacement name for Touchardia glabra non H.St.John, and subgenera are created within Urera s.s. to account for the two morphologically distinct Neotropical clades. This new classification minimises taxonomic and nomenclatural disruption, while more accurately reflecting evolutionary relationships within the group.

A systematic revision of Capparaceae and Cleomaceae in Egypt: an evaluation of the generic delimitations of Capparis and Cleome using ecological and genetic diversity

BackgroundThe Capparaceae family is commonly recognized as a caper, while Cleomaceae represents one of small flowering family within the order Brassicales. Earlier, Cleomaceae was included in the family Capparaceae; then, it was moved to a distinct family after DNA evidence. Variation in habits and a bewildering array of floral and fruit forms contributed to making Capparaceae a “trash-basket” family in which many unrelated plants were placed. Indeed, family Capparaceae and Cleomaceae are in clear need of more detailed systematic revision. ResultsHere, in the present study, the morphological characteristics and the ecological distribution as well as the genetic diversity analysis among the twelve species of both Capparaceae and Cleomaceae have been determined. The genetic analysis has been checked using 15 ISSR, 30 SRAP, and 18 ISTR to assess the systematic knots between the two families. In order to detect the molecular phylogeny, a comparative analysis of the three markers was performed based on the exposure of discriminating capacity, efficiency, and phylogenetic heatmap. Our results indicated that there is a morphological and ecological variation between the two families. Moreover, the molecular analysis confirmed that ISTR followed by SRAP markers has superior discriminating capacity for describing the genetic diversity and is able to simultaneously distinguish many polymorphic markers per reaction. Indeed, both the PCA and HCA data have drawn a successful annotation relationship in Capparaceae and Cleome species to evaluate whether the specific group sort individual or overlap groups. ConclusionThe outcomes of the morphological and ecological characterization along with the genetic diversity indicated an insight solution thorny interspecies in Cleome and Gynandropsis genera as a distinct family (Cleomaceae) and the other genera (Capparis, Cadaba, Boscia, and Maerua) as Capparaceae. Finally, we recommended further studies to elucidate the systematic position of Dipterygium glaucum.

A synopsis of the endemic plant genera of Borneo

The large, tropical island of Borneo has some of the world's richest habitats for plant life, but faces increasing pressures from anthropogenic activities that threaten its biodiversity. With a good portion of the Bornean flora not critically studied, a comprehensive documentation of the numerous endemic taxa expected for the island is not yet complete. It is not known what the relative significance of endemic genera is compared to Bornean centres of endemism documented or predicted through modelling, and if they can inform current conservation plans. As a first step, we here present a synopsis of the endemic genera of Borneo, based on a comprehensive study of literature, herbarium specimens and distributional data, and an investigation of whether the genera have been included in molecular phylogenetic studies that confirm their monophyly. Such a review is timely since many generic delimitations have been shaped by molecular evidence used to test morphology‐based taxonomy, while botanical collection and revisionary efforts continue. Our findings suggest that 65 vascular plant genera from 25 families may be considered endemic to Borneo. More than two‐thirds (48) of these genera have had at least one species included in molecular phylogenetic studies, but of these, only 39 have been sufficiently sampled to be considered monophyletic with high confidence, or they are monotypic. Slightly over half (38) of the endemic genera are herbaceous. A majority of the genera have fruits or seeds specialised for dispersal by abiotic vectors, or unspecialised seeds. Almost two‐thirds (42) of the endemic genera are monotypic, and some of these could represent relict lineages. We expect the current list of endemic genera to be relatively stable and aligned with recent taxonomic concepts, and that it serves to illuminate an interesting aspect of Borneo's unique assemblage of endemic species.

Pollen morphology of the subfamily Salicornioideae (Chenopodiaceae) in Eurasia and North Africa

The pollen morphology of 40 specimens of 15 species belonging to eight genera in the subfamily Salicornioideae (Chenopodiaceae) was studied using light and scanning electron microscopy to evaluate the taxonomic importance of pollen characters. Pollen grains were characteristically pantopolyporate, with 31–51 evenly distributed pores on the surface. The tectum and operculum are covered with minute spinules, typical of other members of the Chenopodiaceae, with minor differences among genera and species. Perforation was seen only in Halostachys belangeriana at high magnification. Pollen characters studied here include pollen and pore diameters, number and density of apertures, interporal distance (chord), chord/pollen diameter ratio, pore diameter/pollen diameter ratio and spinule density on the tectum and operculum. Despite extreme uniformity in pollen morphology, there is good evidence supporting currently known phylogenetic relationships and generic delimitations within the subfamily Salicornioideae. The significant differences in pollen characters among populations of Halostachys belangeriana and Halocnemum strobilaceum may indicate genetic diversity or polyploidy in different populations. The pollen characters provide limited taxonomic value in the subfamily Salicornioideae, which may come from habitat homogeneity of all species growing in hypersaline marshes and inland hygrohalophytic communities.

Taxonomic Revision of two Neotropical Cleomaceae genera, Dactylaena and Haptocarpum

Abstract—We present a taxonomic revision of Dactylaena and Haptocarpum as part of a series of generic revisions and delimitation of Neotropical Cleomaceae. Two new species are described, Dactylaena boliviensis and D. zmarztyae, one new combination is made, D. monandra, four lectotypes are designated in Dactylaena, and a key to all species is presented. This is the first comprehensive revision of the now seven recognized species of Dactylaena and provides needed clarification of species boundaries, distributions, and diversity. Haptocarpum is maintained as a monotypic genus.

Generic boundaries in subtribe Saussureinae (Compositae: Cardueae): Insights from Hyb‐Seq data

AbstractThe subtribe Saussureinae is a highly speciose group with more than 600 species distributed in the Northern Hemisphere and is particularly species‐rich at the high mountains of central and eastern Asia. Saussurea and Jurinea are the two main genera described within the subtribe. However, up to 15 satellite genera are recognized in some recent taxonomic treatments with an analytical viewpoint. For the first time, we carried out a complete sampling to clarify generic boundaries based on a well‐resolved phylogeny of Saussureinae. We employed a Hyb‐Seq technique that targets 1061 nuclear conserved ortholog loci designed for Compositae. After a filtering of potential paralogs, 588 loci were retained to infer phylogenetic trees under concatenation and coalescence approaches. High branch support resolution was recovered at the generic level, but a non‐monophyletic pattern was detected for most of the genera as they are currently circumscribed. Accordingly, we propose a new generic delimitation based on the three main clades recovered in the backbone tree, which are also in agreement with morphological evidence: Dolomiaea, Saussurea, and Jurinea. Following this classification into three genera, 18 new combinations are proposed. This new genus delineation will be used as a basis for future evolutionary studies in the Saussureinae.

Taxonomy and phylogeny of polypores with ganodermatoid basidiospores (Ganodermataceae)

Polypores with complex double-walled basidiospores with a pigmented endosporium ornamented with columns or ridges and a smooth hyaline exosporium are usually classified in the Ganodermataceae. Although the family presents well-delimited morphological features, recent phylogenetic studies have raised divergent evidences about its monophyly. In order to clarify uncertainties of generic delimitation and classification of the group and test its monophyly, morphological analysis and multilocus phylogenetic analyses based on Internal Transcribed Spacer, nuclear 28S rDNA, and portions of the largest subunit of RNA polymerase II and translation elongation factor 1-alpha were carried out. The main outcomes of the study are (i) Ganodermataceae is recovered as monophyletic, (ii) Amaurodermellus is proposed to accommodate the neotropical Amauroderma ovisporum, (iii) Cristataspora is proposed to accommodate two former species of Ganoderma - G. coffeatum and G. flaviporum - with pale context and truncate basidiospores with endosporic ornamentation as ridges. Comments on other species of Ganodermataceae are also presented.

Intraspecific Diversity and Taxonomy of Emmonsia crescens.

Emmonsia crescens is known as an environmental pathogen causing adiaspiromycosis in small rodents. As the generic name Emmonsia is no longer available for this species, its taxonomic position is re-evaluated. The intraspecific variation of Emmonsia crescens was analyzed using molecular, morphological, and physiological data, and the relationship between frequency of adiaspiromycosis and body temperature of host animals was explored. A North American and a pan-global lineage could be discerned, each with subclusters at low genetic distance. European strains produced the classical type of very large adiaspores, while in the North American lineage adiaspores relatively small, resembling the broad-based budding cells of Blastomyces. Members of the closely related genus Emergomyces may exhibit large, broad-based in addition to small, narrow-based budding cells. We conclude that the morphology of the pathogenic phase in these fungi differs gradationally between species and even populations, and is therefore less suitable as a diagnostic criterion for generic delimitation. Two Emmonsia species are reclassified in Emergomyces.

Structural characterization of ITS2 and CBC species concept applications in the tribe Coluteocarpeae (Brassicaceae)

The taxonomic utility of internal transcribed spacer 2 ITS2 secondary structures in different plant groups, as well as in Brassicaceae, has been addressed by many studies. Although characterization and applications of ITS2 secondary structures for the members of main Brassicaceae lineages Lineages I, II, III, and expanded Lineage II have been studied, the utility of compensatory base change CBC species concept has not been the subject of any studies thus far. In the current study, the ITS2 secondary structures of 49 Coluteocarpeae expanded Lineage II specimens were investigated to determine relationships among the species. In addition to the utility of the CBC species concept, the availability of hemi-CBC and nonstructural substitutions NSTs , which are also used for generic and species delimitation, were tested and discussed. A maximum likelihood tree, based on the sequence-structural alignment of the 49 specimens, was constructed to test the different generic assumptions reported by different researchers in the literature. The structural analysis showed that the ITS2 secondary structures of all of the Coluteocarpeae members exhibited a 4-fingered hand model, which was common in the majority of the family members. No CBCs were observed, whereas hemi-CBCs and NSTs were common among the tribe members. Although hemi-CBCs and NSTs were useful for distinguishing most of the Coluteocarpeae species Noccaea aptera Velen. F.K. Mey., Noccaea aghrica P.H. Davis & Kit Tan M. Firat & Ozudogru, Noccaea fendleri A.Gray Holub subsp. glauca A. Nelson Al-Shehbaz & M. Koch, Noccaea griffithiana Boiss. F.K. Mey., Noccaea rubescens Schott & Kotschy ex Boiss. F.K. Mey., etc. , they were not effective for delimitating some problematic species, such as members of Thlaspiceras F.K. Mey. A phylogenetic tree based on the sequence-structural dataset of the ITS2 showed that generic delimitation of Al-Shehbaz was more acceptable due to the fact that Noccaea sensu Al-Shehbaz is monophyletic.

Phylogenetic relationships within the subtribe Cynoglossinae (Cynoglossoideae: Boraginaceae): new insights from nuclear and plastid DNA sequence data

Cynoglossinae with ca. 200 spp. is one of the taxonomically most challenging subtribes of tribe Cynoglosseae with regard to generic delimitations. Here, we present a phylogenetic analysis based on nuclear ITS and cpDNA trnL-F and rps16 sequences of 270 accessions including 102 newly sequenced ones, representing all currently recognized genera of Cynoglossinae to clarify relationships among Cynoglossum and allied genera. We conducted maximum likelihood, maximum parsimony, and Bayesian inference analyses on separate and combined datasets. Cynoglossinae is recovered as a monophylum of closely related genera. Subtribe Cynoglossinae falls into three major groups: (1) Clade I including Microparacaryum spp., (2) Clade II comprising two species of Lindelofia, several Cynoglossum and Paracynoglossum spp., and (3) a larger clade (Clades III + IV) consisting of Solenanthus, Rindera, Trachelanthus, Paracaryum, Pardoglossum, Mattiastrum, and the remainder of Cynoglossum. None of the genera were monophyletic in the combined nuclear-plastid and nuclear datasets, except for Microparacaryum. A close relationship between Solenanthus apenninus and Cynoglossum officinale is shown, which suggests transferring S. apenninus to Cynoglossum. Moreover, Pardoglossum atlanticum, the type of the genus, is placed within Mediterranean Cynoglossum corroborating its synonymy under Cynoglossum. Lindelofia olgae is distantly related to the type of the genus (L. longiflora), but more closely connected with Solenanthus core-group. The majority of species currently recognized as members of Rindera do not form a clade with the type of the genus (R. tetraspis). The genus Paracaryum as currently circumscribed is paraphyletic and includes some species of Mattiastrum and Rindera.

It is not a disaster: molecular and morphologically based phylogenetic analysis of Rondeletieae and the Rondeletia complex (Cinchonoideae, Rubiaceae)

The circumscription of Rondeletieae has changed considerably over time. Historically, 85 genera have been included, characterized by small trees, imbricate corolla aestivation and capsules. Molecular studies led to a narrower circumscription and stressed out that Rondeletieae is mainly an Antillean clade. As historically circumscribed, Rondeletieae is both polyphyletic (involving several tribes, including Condamineae, Sipaneeae, etc.) and paraphyletic with respect to Guettardeae. Uncertainties persist on the tribal circumscription, and its generic limits and relationships. We report results of phylogenetic analyses under parsimony, maximum likelihood and Bayesian analyses including 179 taxa, using concatenated datasets of three chloroplast DNA regions (petD, trnL–F and trnK–matK), their DNA microstructural characters as well as morphology. Our objectives are to: test the monophyly of Rondeletieae and evaluate phylogenetic relationships, evaluate potential characters for tribal and generic delimitation and propose a circumscription for Rondeletieae according to phylogenetic hypothesis using morphological characters. The tribes Guettardeae and Rondeletieae are strongly supported as sister: quincuncial aestivation and spathulate corolla lobes are proposed as a unique combination of characters supporting this relationship. We did not find synapomorphies for each tribe, but there is a set of character combinations that allows distinguishing both tribes that includes the corolla and pollen ornamentation as well as fruit and seed morphology. After evaluating other genera not included in the phylogenies, our proposal is that Rondeletieae contains approximately 120 species in 20 neotropical genera: Acrosynanthus, Acunaeanthus, Blepharidium, Donnellyanthus, Mazaea, Phyllomelia, Rachicallis, Roigella, Rondeletia, Rovaeanthus, Suberanthus, Tainus, plus one tentatively included and recently described (Jamaicanthus).

DdRAD analyses reveal a credible phylogenetic relationship of the four main genera of Bambusa-Dendrocalamus-Gigantochloa complex (Poaceae: Bambusoideae)

The Bambusa-Dendrocalamus-Gigantochloa complex (BDG complex) is the most diversified and phylogenetically recalcitrant group of the paleotropical woody bamboos. Species of this complex occur in tropical and subtropical Asia and most of them are of great economic, cultural and ecological value. The lack of resolution achieved through the analyses of previous molecular datasets has long confounded its phylogenetic estimation and generic delimitation. Here, we adopted a ddRAD-seq strategy to investigate phylogenetic relationships of the four main genera (Bambusa, Dendrocalamus, Gigantochloa, and Melocalamus) in the BDG complex. A total of 102 species were sampled, and SNP data were generated. Both MP and ML analyses of the ddRAD-seq data resulted in a well-resolved topology with Gigantochloa and Melocalamus confirmed as monophyletic, and Melocalamus resolved as sister to the rest of the complex. Bambusa and Dendrocalamus were both resolved as paraphyletic. The phylogenetic relationships were mostly supported by morphological evidence including characters of the branch complement, rachilla, lodicules, filaments and stigma. We also generated and assembled complete plastid genomes of 48 representative species. There were conflicts between the plastome and the ddRAD topologies. Our study demonstrated that RAD-seq can be used to reconstruct evolutionary history of lineages such as the bamboos where ancient hybridization and polyploidy play a significant role. The four genera of the BDG complex have a complex evolutionary history which is likely a product of ancient introgression events.

Fruit and seed micromorphology and its systematic significance in tribe Sorbarieae (Rosaceae)

We investigated fruit and seed morphology in tribe Sorbarieae and one traditionally included genus (Lyonothamnus), which revealed that these characteristics are taxonomically significant for generic delimitation in the tribe Sorbarieae, and two distinct groups in the genus Sorbaria were identified. The following fruit and seed micromorphological characteristics were described: size, shape, texture, the presence/absence of epicuticular wax and, trichomes, testa cell size, and surface ornamentation. Multicellular capitate glands with stalks were only observed on the follicle surfaces of Lyonothamnus. Simple unbranched unicellular non-glandular trichomes were found on the follicles of Chamaebatiaria millefolium, Sorbaria grandiflora, S. sorbifolia complex, and Spiraeanthus schrenkianus. However, Sorbaria arborea complex, S. kirilowii, and S. tomentosa complex had platelet epicuticular wax on their glabrous follicles. Moreover, four types of testa ornamentation were identified: type I, colliculate (Lyonothamnus); type II, reticulate, with straight anticlinal walls and smooth to micro-papillate periclinal walls (Chamaebatiaria); type III, reticulate, with undulate anticlinal walls and smooth periclinal walls (Spiraeanthus); and type IV, reticulate testa ornamentation and divided into two subtypes based on anticlinal and periclinal cell wall patterns (Sorbaria). These studied characteristics identified using principal component analysis may have diagnostic importance among the taxa in the tribe. Our fruit and seed micromorphological results provide strong evidence that genus Lyonothamnus could be positioned in the tribe Lyonothamneae, not Sorbarieae. Moreover, these data supported the preliminary phylogenetic hypothesis that Sorbaria could be divided into two groups.

Newly discovered coralline algae in Southeast Brazil: Tectolithon fluminense gen. et sp. nov. and Crustaphytum atlanticum sp. nov. (Hapalidiales, Rhodophyta)

ABSTRACTTwo new Melobesioideae, Tectolithon fluminense gen. et sp. nov. and Crustaphytum atlanticum sp. nov., were described based on specimens collected at depths from 2 to 30 m in a tropical to subtropical transitional region of Southeast Brazil. Analyses of the plastid-encoded markers psbA and rbcL demonstrated that these taxonomic novelties belong to the clade formed by the typically subarctic/arctic Clathromorphum complex. Tectolithon fluminense has tetra/bisporangial and carposporangial conceptacles that typically become buried in the thallus because of an enveloping process caused by the development of a vegetative rim that grows from the margins of the conceptacle. The rim then fuses and creates a vegetative cover. The development of this vegetative cover is described in detail and its possible convergent evolution in other taxa is discussed. Crustaphytum atlanticum differed morpho-anatomically from the generitype, C. pacificum (the only other known species in this genus), by thallus thickness, maximum number of epithallial cell layers, relative size of subepithallial initials and tetra/bisporangial conceptacle chamber dimensions. The observation of specimens from Tectolithon and Crustaphytum with subepithallial initials that are both longer and shorter than their immediate inward derivatives indicates that this morpho-anatomical character should be used with caution for generic delimitation in the Melobesioideae.

A taxonomic revision of the genus Eriolaena (Malvaceae) in India.

A detailed work on genus Eriolaena archives all names published in a concise nomenclatural review. It is derived from the tribe Dombeya with specific limitations and under the generic delimitation. Detailed taxonomic information & descriptions of all taxa and photographs have been provided for easy identification.

Pollen Morphology and Generic Delimitation of the Polygonaceae in Egypt

POLLEN grains of 18 species representing seven genera (Atraphaxis, Calligonum, Oxygonum, Emex, Periscaria, Polygonum and Rumex) of Polygonaceae Juss. (Subfamily, Polygonoideae) in Egypt were investigated using light microscopy (LM) and scanning electron microscopy (SEM) to evaluate the taxonomic value of micro-morphological characters of pollen grains in order to differentiate between the genera and species. The study showed that pollen grains are radially symmetrical, isopolar, oblate-spheroidal, spheroidal, subprolate to prolate, with ambtrilobed or circular, tricolporoidate, tricolporate, rarely tetracolporate and pantopolyporate. Tectum is striato-reticulate to reticulate, coarse reticulate with double bacula in muri and pilatelumine, rugulo-reticulate, microechinate-foveolate, and microgranulate-perforate Based on these characters, five groups of pollen types are recognized. The results indicate that pollen morphology characters of shape, aperture and exine ornamentation are useful in generic delimitation. A key for the separation of the different pollen types is provided.

Phylogenomic analyses of thePhotiniacomplex support the recognition of a new genusPhippsiomelesand the resurrection of a redefinedStranvaesiain Maleae (Rosaceae)

AbstractPhotiniaand its morphologically similar allies in Maleae (Rosaceae) consist of five currently recognized genera:Aronia, Heteromeles, Photinia, Pourthiaea, andStranvaesia, and 68 species, distributed in Asia and North and Central America. Despite previous efforts to clarify relationships in this group, the generic delimitations have remained uncertain. Our goals were to reconstruct a robust phylogeny ofPhotiniaand its close allies to test the monophyly of the currently recognized genera, especiallyPhotiniaandStranvaesia, and the hybrid origin hypothesis ofPhotinia bodinieri. This study employs complete plastomes and the entire nuclear ribosomal DNA (nrDNA) repeats assembled from the genome skimming approach with a broad taxon sampling of 81 species in 30 genera of Rosaceae, especially Maleae. Based on three datasets, including the whole plastome, coding sequence, and nrDNA repeats, the results of maximum likelihood and Bayesian inference analyses showed that the previously circumscribedStranvaesiaandPhotiniawere each non‐monophyletic. Six clades have been recovered herein withinPhotiniaand its allied genera:Aronia, Heteromeles, Photinias.s.,Pourthiaea, Stranvaesia, and a new genusPhippsiomelesconsisting of the Central American species formerly placed inPhotinia. The strong conflicts between the plastome and nrDNA phylogenies ofPhippsiomelesandStranvaesia tomentosasuggest the possibility that they may have each originated involving hybridization events, while no incongruence among datasets was detected to support the hybrid origin ofPhotinia bodinieri. We provide 12 new combinations, to transfer eight taxa of the New WorldPhotiniaintoPhippsiomelesand clarify the generic placements of several species ofPhotiniaandStranvaesia.