Species Concept Research Articles

A decadal study reveals that restoration guided by an umbrella species does not reach target levels

Abstract Maintaining structural and functional elements of ecosystems are essential in order to preserve biodiversity and ecosystem function. As a means of guiding conservation work, the umbrella species concept was developed. In Sweden, one putative umbrella species, the white‐backed woodpecker, has guided conservation and restoration of deciduous forests for two decades. Here, we evaluate the decadal effects of restoration aimed at the white‐backed woodpecker on biodiversity of saproxylic beetles. We compare stands that were restored 12 to 21 years ago to non‐restored stands and historical white‐backed woodpecker habitats acting as restoration target stands. Restored stands contained higher deciduous deadwood volumes than non‐restored stands but lower volumes than restoration target stands. The deadwood in restored stands was concentrated in later decay stages, whereas target stand deadwood was more evenly distributed across decay stages. Restored stands had similar species richness and abundance of most groups of saproxylic beetles compared with non‐restored stands while not reaching the levels of restoration target stands. Species assemblages differed among all stand types with restored stands supporting late decay stage and generalist species while target stands supported more deciduous associated and threatened species. Synthesis and applications: We conclude that after one to two decades, restoration improve stand structure and benefit beetle diversity but that target levels are not yet reached. Thus, only partial restoration is achieved. Our results stress that for restoration to be successful both continuous and repeated restoration efforts are needed and that it is important to identify target levels of important habitat characteristics when assessing restoration outcome.

Patterns, processes and conservation management consequences of intraspecific diversity, illustrated by fishes from recently glaciated lakes

Abstract Patterns in phenotypic and genotypic diversity within many species are becoming increasingly apparent, although there remain many species for which such patterns have yet to be described adequately. Fishes from recently glaciated ecosystems are likely to be particularly rich in intraspecific diversity, yet current conservation management strategies are, in many parts of the world, particularly in Europe, conventionally and overwhelmingly focused on species, regardless of competing species concepts, and appropriate policies for managing diversity at a sub‐specific level still have to be developed. Occasional attempts to protect certain vulnerable ecotypes and proposed alternative units of conservation (e.g. ‘Pragmatic Species’ or ‘Evolutionarily Significant Units’) reinforce the conventional primacy of contemporary expressed patterns of variation. Intraspecific phenotypic and genotypic patterns are ultimately the result of complex processes of divergence; conservation approaches that focus on the products of evolution largely ignore the processes that generate and maintain those patterns. Policies that acknowledge the continuation of evolution, the derivation of novel diversity over often very short time spans and the role of environment in initiating and perpetuating these processes are poorly integrated into management strategy. To address possible deficits, where intraspecific diversity is not addressed in management practice, we believe it to be important first to characterize hidden genetic and phenotypic diversity, which may intimate eco‐evolutionary processes, initially among species of high conservation status. A second step should be to use an approach to intraspecific diversity that illuminates the ultimate processes and mechanisms that bring about that diversity, which also concedes the central role of the environment and affords adequate protection to the ecosystems that drive these processes, such as the United Nations Convention on Biological Diversity (CBD) Ecosystems approach.

Redescription and revised genus placement of Oliarus pinicolus Osborn, 1926, with notes on Antillean Pentastirini (Hemiptera: Fulgoromorpha: Cixiidae).

Oliarus pinicolus Osborn, 1926 is a little-known planthopper described from western Cuba on Cuban pine (Pinus cubensis). As part of a review of the sprawling New World cixiid genus Melanoliarus Fennah, 1945, the species is herein redescribed and illustrated for the first time, including the male terminalia. After comparison to similar species in the region, we transfer the species to Nivcentia Holzinger, 2004, as Nivcentia pinicolus comb. nov., based on characteristics of the male terminalia and provide an amended description of the genus. We also designate a lectotype for Oliarus pinicolus to ensure the stability of the species concept described here. A checklist of Antillean Pentastirini is included with taxonomic comments on the species and genera of the region. The pentastirine species of Cuba are illustrated.

Parallels of quantum superposition in ecological models: from counterintuitive patterns to eco-evolutionary interpretations of cryptic species

BackgroundSuperposition, i.e. the ability of a particle (electron, photon) to occur in different states or positions simultaneously, is a hallmark in the subatomic world of quantum mechanics. Although counterintuitive at first sight, the quantum world has potential to inform macro-systems of people and nature. Using time series and spatial analysis of bird, phytoplankton and benthic invertebrate communities, this paper shows that superposition can occur analogously in redundancy analysis (RDA) frequently used by ecologists.ResultsWe show that within individual ecosystems single species can be associated simultaneously with different orthogonal axes in RDA models, which suggests that they operate in more than one niche spaces. We discuss this counterintuitive result in relation to the statistical and mathematical features of RDA and the recognized limitations with current traditional species concepts based on vegetative morphology.ConclusionWe suggest that such “quantum weirdness” in the models is reconcilable with classical ecosystems logic when the focus of research shifts from morphological species to cryptic species that consist of genetically and ecologically differentiated subpopulations. We support our argument with theoretical discussions of eco-evolutionary interpretations that should become testable once suitable data are available.

Evaluating Spatial Coverage of the Greater Sage-Grouse Umbrella to Conserve Sagebrush-Dependent Species Biodiversity within the Wyoming Basins

Biodiversity is threatened due to land-use change, overexploitation, pollution, and anthropogenic climate change, altering ecosystem functioning around the globe. Protecting areas rich in biodiversity is often difficult without fully understanding and mapping species’ ecological niche requirements. As a result, the umbrella species concept is often applied, whereby conservation of a surrogate species is used to indirectly protect species that occupy similar ecological communities. One such species is the greater sage-grouse (Centrocercus urophasianus), which has been used as an umbrella to conserve other species within the sagebrush (Artemisia spp.) ecosystem. Sagebrush-steppe ecosystems within the United States have experienced drastic loss, fragmentation, and degradation of remaining habitat, threatening sagebrush-dependent fauna, resulting in west-wide conservation efforts to protect sage-grouse habitats, and presumably other sagebrush wildlife. We evaluated the effectiveness of the greater sage-grouse umbrella to conserve biodiversity using data-driven spatial occupancy and abundance models for seven sagebrush-dependent (obligate or associated) species across the greater Wyoming Basins Ecoregional Assessment (WBEA) area (345,300 km2) and assessed overlap with predicted sage-grouse occurrence. Predicted sage-grouse habitat from empirical models only partially (39–58%) captured habitats identified by predicted occurrence models for three sagebrush-obligate songbirds and 60% of biodiversity hotspots (richness of 4–6 species). Sage-grouse priority areas for conservation only captured 59% of model-predicted sage-grouse habitat, and only slightly fewer (56%) biodiversity hotspots. We suggest that the greater sage-grouse habitats may be partially effective as an umbrella for the conservation of sagebrush-dependent species within the sagebrush biome, and management actions aiming to conserve biodiversity should directly consider the explicit mapping of resource requirements for other taxonomic groups.

A review of the woody bamboos (Poaceae: Bambusoideae: Bambuseae) of Trinidad and Tobago

Trinidad and Tobago are important islands to Neotropical woody bamboo taxonomy. Trinidad is a type locality for two widely applied names with poorly defined species concepts: Arthrostylidium pubescens and A. excelsum, and two potentially endemic species: Chusquea cylindrica and Rhipidocladum prestoei. Few resources exist for the islands to adequately identify all the woody bamboo species that putatively grow there. The serialized vascular flora of Trinidad and Tobago (1928–1992), for instance, lacks a treatment for Poaceae. Moreover, the most speciose native genus, Arthrostylidium, is only partially revised, with the emphasis on the South American species and not those of the West Indies. Our objective is to critically review the woody bamboos of Trinidad and Tobago, clarify which species are or have been known from the islands, and provide an identification key, species accounts and distribution maps for the revised list of taxa. We conducted fieldwork campaigns in 2021–2023, and reviewed herbarium specimens and human observation records of woody bamboos from the islands. Newly collected specimens were vouchered and all woody bamboo records were georeferenced and plotted using QGIS. We confirmed two species of native woody bamboo and four species of introduced woody bamboo were extant on Trinidad. An additional three Western Hemisphere species have historic records of occurrence on the islands. Native species diversity correlated well with previously identified floristic hotspots. One introduced species, Bambusa vulgaris, is common on both islands. To the best of our knowledge, there are currently no native woody bamboo species present on Tobago, however, A. pubescens appears to have been growing along the Main Ridge in the past. The historic presence of some species not currently found may be the result of dynamic and/or stochastic colonization events among the islands and mainland South America.

A lineage perspective on hominin taxonomy and evolution.

An uncritical reliance on the phylogenetic species concept has led paleoanthropologists to become increasingly typological in their delimitation of new species in the hominin fossil record. As a practical matter, this approach identifies species as diagnosably distinct groups of fossils that share a unique suite of morphological characters but, ontologically, a species is a metapopulation lineage segment that extends from initial divergence to eventual extinction or subsequent speciation. Working from first principles of species concept theory, it is clear that a reliance on morphological diagnosabilty will systematically overestimate species diversity in the fossil record; because morphology can evolve within a lineage segment, it follows that early and late populations of the same species can be diagnosably distinct from each other. We suggest that a combination of morphology and chronology provides a more robust test of the single-species null hypothesis than morphology alone.

Steinernema yirgalemense (Steinernematidae) to control Phlyctinus callosus and Phlyctinus xerophilus (Curculionidae)

Summary Considerable progress has been made in the surveying, taxonomy, screening, mass production and formulation of entomopathogenic nematodes (EPN) and their associated symbiotic bacteria in South Africa. Steinernema yirgalemense isolate 157-C is one of the most promising native EPN candidates with regards to virulence, its broad insect-host spectrum, and can be readily mass-produced and formulated into a commercial product. The banded fruit weevils, Phlyctinus callosus sensu stricto and Phlyctinus xerophilus, previously grouped together under the Phlyctinus callosus sensu lato species concept, are native entimine weevils of economic importance to deciduous fruit, grapevine and berries in the Western Cape province of South Africa. This study investigated potential differences in baseline susceptibility of larvae and pupae of the two weevil species to S. yirgalemense in laboratory screenings. The test arena used was 24-well bioassay plates, with an inoculation concentration of 200 infective juveniles (IJ) insect−1 for larvae and 100 IJ insect−1 for pupae. Infection was determined 48 h and 96 h after inoculation. Field-efficacy of S. yirgalemense, applied at a concentration of 60 IJ cm−2, against larvae of the two weevil species was determined in an ecologically relevant semi-field trial. In all cases in vitro mass-produced IJ of S. yirgalemense were used. No baseline differential susceptibility between P. callosus and P. xerophilus larvae was obtained in laboratory screenings. Phlyctinus pupae were approximately twice as susceptible compared to larvae, with significant differences between bioassay batches. Approximately 45% control of P. xerophilus larvae was obtained after 96 h of exposure to S. yirgalemense in the field, differing significantly from the control and P. callosus treatment. Low levels of Phlyctinus larval infection by native EPN (confirmed as Heterorhabditis bacteriophora from one P. xerophilus cadaver) occurred in both control and EPN treatment groups under field conditions.

Screening of among seventeen sunflowers (Helianthus annuus L.) genotypes for oil content and the first flowering day using random amplified polymorphic DNA markers

Background Sunflower refers to the tribe Helianthus, subtribe Helianthinae, and family Asteraceae, which collectively contains 20 genera and 400 species. An important oilseed crop that yields edible oil is Helianthus annuus L. Objective The primary goal of the current study was to assess the genetic diversity of 17 genotypes of sunflower (Helianthus annuus L) To measure the oil content during the initial flowering period and to reach the highest percentage of oil can be obtained from the first flowering day. Materials and methods Five RAPD (random amplified polymorphic DNA) primers were used to detect the genetic diversity of the 17 sunflower hybrid genotypes obtained from Spain. Phylogenetic relationships of 17 sunflower genotypes were determined using three replications and 6 m lines on August 15, 2019, at the National Research Centre farm in Nubaria as part of a donation from the German corporation (strobe), Spain. To analyze the genetic diversity and phylogenetic linkages in sunflower germplasm, DNA fingerprinting and the Random Amplified Polymorphic DNA (RAPD) molecular marker approach were also used. Results and conclusion The oil content of 17 sunflower genotypes (Helianthus annuus L.) was assessed, with values ranging from 46 to 50%, with the highest values falling into five genotypes. However, the two genotypes were found to have the lowest oil percentage (46%). The early age and oil percentage differed among the varieties. In the Tornado and Elves genotypes, the longest and shortest days were 59 and 47, respectively. The means and standard errors for all statistical data are reported. Statistical significance was evaluated using the LSD. P values were considered statistically significant at P less than or equal to 0.05. According to the findings, RAPD primers generated 49 bands with a size range of 0.1–3 kb and an 87.75% polymorphism percentage. For RAPD, 43 polymorphic bands with distinct bands were observed. Morphological features and RAPD analysis separated the UPGMA Dendrogram into three groups. Jaccard’s coefficient was used to analyze the genetic similarity matrix, and a morphological study revealed that Tornado and Elvas, both from Spain, shared the most genetic similarity (0.970). RAPD analysis and morphological features are useful in identifying genetic variants. Conclusion, according to our findings, Helianthus annuus L. has a significant variation ratio. Indicating substantial diversity across the 17 sunflower genotypes, the genetic similarity index calculated using pooled data from RAPD markers showed an extensive range from 0.645 to 0.986. This study may be a reference for future research on Helianthus annuus L. and may support breeding initiatives and species concepts.

Beyond Animal Charisma: A Sociological Approach to Charismatic Species

Abstract Sociologists have been debating the nature of charisma since the discipline’s inception. Recent debates in the sociology of charisma concern the role of social interaction and the place of organisations in the generation of charisma. As these debates have developed, the interdisciplinary field of conservation has begun to debate the concept of charismatic species. To date, literature from the conservation sciences has identified those species most likely to be identified as charismatic and those variables most frequently associated with charismatic species. However, little theorising has been done on the causes of charisma in charismatic species. This article uses the case of charismatic species to outline sociological arguments about charisma more generally. This theoretical exercise advances the literature in both sociology and conservation in several ways. For sociologists, the case of charismatic species shows that seemingly competitive models of charisma are in fact complementary. For those interested in the uses of charismatic species for conservation, this article demystifies charismatic species, demonstrating the ways in which they are historically and socially constructed.

An appraisal of taxonomic issues in Lower to mid-Cretaceous mesorbitolinids (larger benthic foraminifera)

Species differentiation within the genus Mesorbitolina Schroeder 1962 is primarily based on the general structure of the megalospheric embryo and its biometrics. The taxonomy of three taxa, namely Mesorbitolina texana (Roemer 1849), Mesorbitolina subconcava (Leymerie 1878) and Mesorbitolina pervia (Douglass 1960) is complicated due to differing species concepts between authors, and, in the case of the first two named, by missing type designations in the original descriptions as well as disagreements with respect to their type-localities. Herein, it is demonstrated that M. pervia is the junior synonym of Mesorbitolina birmanica (Sahni 1937) due to priority reasons, both taxa characterized by a similar-sized plano-convex protoconch. Some concepts of M. texana and M. subconcava can also be placed in M. birmanica, but not those as defined by lectotypes. Published data for M. birmanica suggest a late Aptian (late Gargasian) to early (? late) Albian age and a cosmopolitan distribution. Mesorbitolina texana appears slightly earlier in the late Aptian persisting into the middle Albian, and a distribution ranging from the southern USA to the Middle East.

Fusarium species causing root rot and wilt in tomato in Brazil

AbstractA high frequency of plants showing symptoms of wilting and root rot has been observed in tomato‐producing areas in Santarém and Belterra, Pará, Brazil. These plants showed symptoms ranging from yellowing to wilting, with roots displaying reduced development and darkening of the xylem. Four fungal isolates, derived from a collection of 12 obtained from symptomatic plants, were chosen for identification using both morphological and phylogenetic species concepts. To determine the identity of the fungi, DNA was extracted and used in PCR reactions. PCR products were sequenced from the TEF‐1α and RBP2 regions and compared with sequences in GenBank using BLASTn. Based on the phylogenetic analyses, the isolates were identified as Fusarium falciforme and Fusarium suttonianum, belonging to the species complex Fusarium solani – (FSSC), and Fusarium triseptatum, belonging to the species complex Fusarium oxysporum – (FOSC). The fourth isolate, COUFPI 295, grouped within a clade of F. kalimantanense and F. sangayamense from FOSC. The fulfilment of Koch's postulates confirmed that all isolates induced symptoms of root rot and concomitant reduction in root mass, leading to observable wilting symptoms. This is the first report of F. suttonianum, F. falciforme and F. triseptatum causing root rot and wilt in tomato plants in Brazil.

Cladistic species definitions can lead to under-representation of biodiversity from adaptive radiations

Abstract Many species are paraphyletic, but current taxonomic practices often do not recognize this, and attempts are made to apply a monophyletic species concept. While allowing the recognition of ecomorphologically equivalent, or even phenotypically indistinguishable allopatric, taxa as species, this often leads to combining distinctive local forms (such as cave-adapted populations) or even whole adaptive radiations (often in lakes) with widespread paraphyletic species to force species monophyly. It is suggested that this has negative consequences for our documentation and understanding of biodiversity, as well as for conservation, through issues such as lack of IUCN red-listing.

A microbial perspective on speciation

Abstract Understanding what a microbial species is and the process of speciation in microbes has been and still is a puzzle with many challenges. But there is now emerging consensus that speciation in microbes does follow certain rules and limitations. Just like in macrobes, it can be driven by divergent natural selection and is maintained by barriers to gene flow, either genetic or ecological in nature. However, whether microbial speciation mirrors that of sexually reproducing eukaryotes is up for debate, as extensive horizontal gene flow can blur patterns and processes. Here, I provide intriguing examples of speciation in bacteria, viruses, and yeast, which are arguably similar to what we see in eukaryotes. I synthesize recent insights from microbial evolutionary genomics, which may mitigate the traditional view that microbes are ‘messy’ and do not fit eukaryotic species concepts and speciation models. Finally, I highlight the benefits of microbial experimental evolution to answer fundamental questions in speciation research (especially why, how, and when speciation occurs). Speciation research with microbes, as opposed to the organisms traditionally used in this field, may suffer less from observational bias and the experimental control we have over selection types, gene flow, and reproductive modes in microbial systems may allow us to determine the mechanisms and timing of ecological divergence, reproductive isolation, and speciation.

Species Delimitation in Sciadocladus (Pterobryellaceae, Bryophyta)

Sciadocladus is a distinctive genus of large dendroid mosses restricted to New Zealand, New Caledonia and the Solomon Islands. Of the two extant species, S. kerrii is endemic to New Zealand, while S. menziesii is found in New Zealand, New Caledonia and the Solomon Islands. Populations of S. menziesii from New Caledonia and the Solomons have been recognised as subspecies splendidum, distinct from the New Zealand populations. Given the geographical isolation of the two subspecies of S. menziesii, we hypothesised that the endemic S. kerrii could have arisen in situ in New Zealand through speciation from S. menziesii subsp. menziesii. This would make these two taxa more closely related to each other than S. menziesii subsp. menziesii is to S. menziesii subsp. splendidum, challenging the species concept of S. menziesii. We tested this hypothesis by conducting a phylogenetic analysis of molecular data from multiple exemplars of Sciadocladus, including material from both New Zealand and New Caledonia. The results show all specimens of S. menziesii strongly supported as monophyletic, sister to a clade comprising S. kerrii specimens, thus rejecting the hypothesis and corroborating the established taxonomy. Implications for interpretation of the phylogeographic history of the genus are discussed.

Another remarkable new species of Dictyanthus (Apocynaceae, Asclepiadoideae, Asclepiadeae, Gonolobinae) with a long stylar head from Mexico

Dictyanthus includes 17 climbing species distributed from northern Mexico to Nicaragua. Mexico is its main center of diversification with 15 endemic species. The genus is known for its conspicuous flowers with high ornamental potential. Dictyanthus species are distinguished by the shape of their corolla (campanulate or rotated), their pattern of color lines or reticulations on the corolla lobes, the size and shape of their corona, and the shape of the stylar head. The present work formally names as a new species, and describes and illustrates the plants with a long and conspicuous stylar head, distinguishing it from the rest of its relatives. The study consisted of field work for two years, as well as a review of herbarium material and literature. The description of the organism was based on in situ morphology, herbarium material and specimens preserved in ethanol. The conservation assessment was based on IUCN criteria. We follow the cohesive species concept as an explanatory hypothesis for the taxa. A dichotomous key and comparative plates are presented for species with stylar head projection. Dictyanthus unicornus differs from other species in the genus by its conspicuously elongated stylar head and the combination of patent corolla lobes and fleshy, spatulate crown lobes protruding from the corolla throat. According to IUCN criteria, this species is considered Endangered. With the present discovery, the genus Dictyanthus reaches 18 described species of which 16 endemic to Mexico.

Reactive transport model for bentonites in COMSOL multiphysics: Benchmark and validation exercise

At present, the deep geological repository concept for spent nuclear fuel is considered the most reliable and safe technique for the permanent disposal of this type of waste. One of the many safety elements used is an engineered barrier made of compacted bentonite. This material allows the encapsulated waste to be isolated from the host rock. Therefore, there is great interest in a detailed study of the behavior of bentonites to different changes in the composition of the surrounding groundwater.In this context, this work presents a new reactive transport model for bentonites implemented in the COMSOL Multiphysics platform. The model contemplates a non-simplistic geochemical system composed of 42 species and 4 minerals. Reactive transport involves the diffusive-dispersive-advective processes defined by the Nernst Planck equations for two overlapping modeling levels (macro- and microstructural) to simulate the behavior of double-porosity media. The uniqueness of this model is that the system of equations used to calculate the chemical speciation problem and the advective-diffusive-dispersive transport can be integrally solved in COMSOL. The model has been satisfactorily verified and validated using the benchmark exercise consisting of the simulation of the multicomponent advective-diffusive column experiment conducted on a compacted bentonite core extracted from a field experiment (LOT project) in the Äspö Hardrock laboratory (Sweden).

The species problem in Artemia Leach, 1819 (Crustacea: Anostraca), a genus with sexual species and obligate parthenogenetic lineages

Abstract Parthenogenesis is an asexual reproduction mode characterized by the development of a female oocyte without fertilization. From an evolutionary perspective, parthenogenesis seems less successful than the predominant sexual mode, though there are groups in which both reproductive types exist, an example of which is the genus Artemia Leach, 1819. This salt-tolerant crustacean inhabiting hypersaline environments contains regionally endemic sexual species and obligate parthenogenetic groups with different ploidy levels, collectively referred to as Artemia parthenogenetica. Here, we discuss the difficulties of using a common species concept in Artemia Leach, 1819. While sexual species are widespread and fit the Biological Species Concept (BSC), which emphasizes reproductive isolation to maintain species genetic integrity or cohesiveness, it does not apply to uniparental organisms originating from sexual species with major meiotic changes. We show that different ploidy levels of parthenogenetic Artemia groups with uniform nuclear gene pools are maternally independent genetic entities (or cohesive), collectively and wrongly referred to as Artemia parthenogenetica. Thus, we conclude that ‘Artemia parthenogenetica’ is an invalid nominal specific name. Additionally, parthenogenetic Artemia groups cannot be considered a form of Artemia species (A. urmiana and/or A. sinica). In conclusion, we recommend using the term ‘parthenogenetic lineage(s)’ instead of ‘parthenogenetic population(s)’ to describe asexual Artemia group(s), because in modern population genetics and systematics, the term ‘population’ refers to interbreeding individuals with sexual reproduction. Furthermore, it clarifies that parthenogenetic lineages of Artemia are native to Mediterranean biodiversity.

CONTRIBUTION TO THE GENUS SYMPETRUM NEWMAN, 1833 (ODONATA, ANISOPTERA) FROM SW ROMANIA, WITH A GENERAL DISCUSSION ON SYMPETRUM SPECIES

The paper presents the results of an exploratory research on the genus Sympetrum in two regions in the SW part of Romania (Timiș Plain and Oltenia region), in terms of the faunistic account, species distribution and comparative morphology. The variable, constant and distinctive characters are given for each species. The variability of some taxonomic characters – pterostigma, the male accessory genitalia and the vulvar scale is compared with data from the available literature. The analysis reveals that pterostigma variability and set (combinations) of morphological characters (legs and vulvar scale) go out of the current knowledge, questioning their taxonomic value. A discussion on Sympetrum species is provided from the perspective of the classical principles of systematic zoology: the biological species concept, the reproductive isolation of species, species delimitation, speciation.

Phytophthora : taxonomic and phylogenetic revision of the genus.

Many members of the Oomycota genus Phytophthora cause economic and environmental impact diseases in nurseries, horticulture, forest, and natural ecosystems and many are of regulatory concern around the world. At present, there are 223 described species, including eight unculturable and three lost species. Twenty-eight species need to be redescribed or validated. A lectotype, epitype or neotype was selected for 20 species, and a redescription based on the morphological/molecular characters and phylogenetic placement is provided. In addition, the names of five species are validated: P. cajani, P. honggalleglyana (Synonym: P. hydropathica), P. megakarya, P. pisi and P. pseudopolonica for which morphology and phylogeny are given. Two species, P. ×multiformis and P. uniformis are presented as new combinations. Phytophthora palmivora is treated with a representative strain as both lecto- and epitypification are pending. This manuscript provides the updated multigene phylogeny and molecular toolbox with seven genes (ITS rDNA, β-tub, COI, EF1α, HSP90, L10, and YPT1) generated from the type specimens of 212 validly published, and culturable species (including nine hybrid taxa). The genome information of 23 types published to date is also included. Several aspects of the taxonomic revision and phylogenetic re-evaluation of the genus including species concepts, concept and position of the phylogenetic clades recognized within Phytophthora are discussed. Some of the contents of this manuscript, including factsheets for the 212 species, are associated with the "IDphy: molecular and morphological identification of Phytophthora based on the types" online resource (https://idtools.org/tools/1056/index.cfm). The first version of the IDphy online resource released to the public in September 2019 contained 161 species. In conjunction with this publication, we are updating the IDphy online resource to version 2 to include the 51 species recently described. The current status of the 223 described species is provided along with information on type specimens with details of the host (substrate), location, year of collection and publications. Additional information is provided regarding the ex-type culture(s) for the 212 valid culturable species and the diagnostic molecular toolbox with seven genes that includes the two metabarcoding genes (ITS and COI) that are important for Sanger sequencing and also very valuable Molecular Operational Taxonomic Units (MOTU) for second and third generation metabarcoding High-throughput sequencing (HTS) technologies. The IDphy online resource will continue to be updated annually to include new descriptions. This manuscript in conjunction with IDphy represents a monographic study and the most updated revision of the taxonomy and phylogeny of Phytophthora, widely considered one of the most important genera of plant pathogens. Taxonomic novelties: New species: Phytophthora cajani K.S. Amin, Baldev & F.J. Williams ex Abad, Phytophthora honggalleglyana Abad, Phytophthora megakarya Brasier & M.J. Griffin ex Abad, Phytophthora pisi Heyman ex Abad, Phytophthora pseudopolonica W.W. Li, W.X. Huai & W.X. Zhao ex Abad & Kasiborski; New combinations: Phytophthora ×multiformis (Brasier & S.A. Kirk) Abad, Phytophthora uniformis (Brasier & S.A. Kirk) Abad; Epitypifications (basionyms): Peronospora cactorum Lebert & Cohn, Pythiacystis citrophthora R.E. Sm. & E.H. Sm., Phytophthora colocasiae Racib., Phytophthora drechsleri Tucker, Phytophthora erythroseptica Pethybr., Phytophthora fragariae Hickman, Phytophthora hibernalis Carne, Phytophthora ilicis Buddenh. & Roy A. Young, Phytophthora inundata Brasier et al., Phytophthora megasperma Drechsler, Phytophthora mexicana Hotson & Hartge, Phytophthora nicotianae Breda de Haan, Phytophthora phaseoli Thaxt., Phytophthora porri Foister, Phytophthora primulae J.A. Toml., Phytophthora sojae Kaufm. & Gerd., Phytophthora vignae Purss, Pythiomorpha gonapodyides H.E. Petersen; Lectotypifications (basionym): Peronospora cactorum Lebert & Cohn, Pythiacystis citrophthora R.E. Sm. & E.H. Sm., Phytophthora colocasiae Racib., Phytophthora drechsleri Tucker, Phytophthora erythroseptica Pethybr., Phytophthora fragariae Hickman, Phytophthora hibernalis Carne, Phytophthora ilicis Buddenh. & Roy A. Young, Phytophthora megasperma Drechsler, Phytophthora mexicana Hotson & Hartge, Phytophthora nicotianae Breda de Haan, Phytophthora phaseoli Thaxt., Phytophthora porri Foister, Phytophthora primulae J.A. Toml., Phytophthora sojae Kaufm. & Gerd., Phytophthora vignae Purss, Pythiomorpha gonapodyides H.E. Petersen; Neotypifications (basionym): Phloeophthora syringae Kleb., Phytophthora meadii McRae Citation: Abad ZG, Burgess TI, Bourret T, Bensch K, Cacciola S, Scanu B, Mathew R, Kasiborski B, Srivastava S, Kageyama K, Bienapfl JC, Verkleij G, Broders K, Schena L, Redford AJ (2023). Phytophthora: taxonomic and phylogenetic revision of the genus. Studies in Mycology 106: 259-348. doi: 10.3114/sim.2023.106.05.