Corvisyringophilus, a New Genus in the Family Syringophilidae (Acariformes: Prostigmata) and Its Phylogenetic Position among Primitive Genera.

An increasing number of plant-insect studies using phylogenetic analysis suggest that cospeciation events are rare in plant-insect systems. Instead, nonrandom patterns of phylogenetic congruence are produced by phylogenetically conserved host switching (to related plants) or tracking of particular resources or traits (e.g., chemical). The dominance of host switching in many phytophagous insect groups may make the detection of genuine cospeciation events difficult. One important test of putative cospeciation events is to verify whether reciprocal speciation is temporally plausible. We explored techniques for double-dating of both plant and insect phylogenies. We use dated molecular phylogenies of a psyllid (Hemiptera)-Genisteae (Fabaceae) system, a predominantly monophagous insect-plant association widespread on the Atlantic Macaronesian islands. Phylogenetic reconciliation analysis suggests high levels of parallel cladogenesis between legumes and psyllids. However, dating using molecular clocks calibrated on known geological ages of the Macaronesian islands revealed that the legume and psyllid radiations were not contemporaneous but sequential. Whereas the main plant radiation occurred some 8 million years ago, the insect radiation occurred about 3 million years ago. We estimated that >60% of the psyllid speciation has resulted from host switching between related hosts. The only evidence for true cospeciation is in the much more recent and localized radiation of genistoid legumes in the Canary Islands, where the psyllid and legume radiations have been partially contemporaneous. The identification of specific cospeciation events over this time period, however, is hindered by the phylogenetic uncertainty in both legume and psyllid phylogenies due to the apparent rapidity of the species radiations.

First detection of Anaplasma phagocytophilum in quill mites (Acari: Syringophilidae) parasitizing passerine birds

BackgroundUsing phylogenetic approaches, the expectation that parallel cladogenesis should occur between parasites and hosts has been validated in some studies, but most others provided evidence for frequent host shifts. Here we examine the evolutionary history of the association between Microbotryum fungi that cause anther smut disease and their Caryophyllaceous hosts. We investigated the congruence between host and parasite phylogenies, inferred cospeciation events and host shifts, and assessed whether geography or plant ecology could have facilitated the putative host shifts identified.For cophylogeny analyses on microorganisms, parasite strains isolated from different host species are generally considered to represent independent evolutionary lineages, often without checking whether some strains actually belong to the same generalist species. Such an approach may mistake intraspecific nodes for speciation events and thus bias the results of cophylogeny analyses if generalist species are found on closely related hosts. A second aim of this study was therefore to evaluate the impact of species delimitation on the inferences of cospeciation.ResultsWe inferred a multiple gene phylogeny of anther smut strains from 21 host plants from several geographic origins, complementing a previous study on the delimitation of fungal species and their host specificities. We also inferred a multi-gene phylogeny of their host plants, and the two phylogenies were compared. A significant level of cospeciation was found when each host species was considered to harbour a specific parasite strain, i.e. when generalist parasite species were not recognized as such. This approach overestimated the frequency of cocladogenesis because individual parasite species capable of infecting multiple host species (i.e. generalists) were found on closely related hosts. When generalist parasite species were appropriately delimited and only a single representative of each species was retained, cospeciation events were not more frequent than expected under a random distribution, and many host shifts were inferred.Current geographic distributions of host species seemed to be of little relevance for understanding the putative historical host shifts, because most fungal species had overlapping geographic ranges. We did detect some ecological similarities, including shared pollinators and habitat types, between host species that were diseased by closely related anther smut species. Overall, genetic similarity underlying the host-parasite interactions appeared to have the most important influence on specialization and host-shifts: generalist multi-host parasite species were found on closely related plant species, and related species in the Microbotryum phylogeny were associated with members of the same host clade.ConclusionWe showed here that Microbotryum species have evolved through frequent host shifts to moderately distant hosts, and we show further that accurate delimitation of parasite species is essential for interpreting cophylogeny studies.

Simple SummaryMites of the family Syringophilidae (Acariformes: Cheyletoidea)—also called quill mites—are permanent and highly specialized ectoparasites of birds living inside the calamus of the various types of the feathers. In the present paper, we conducted a study focused on prevalence, host specificity, networks, and phylogeny of the syringophilid mites parasitizing on pigeon and doves (Columbiformes). We postulate that the Syringophilidae mites and Columbiformes bird system represent a model which can be used in a broader study of the relationship between hosts and parasites.The quill mites belonging to the family Syringophilidae (Acari: Prostigmata: Cheyletoidea) are obligate ectoparasites of birds. They inhabit different types of the quills, where they spend their whole life cycle. In this paper, we conducted a global study of syringophilid mites associated with columbiform birds. We examined 772 pigeon and dove individuals belonging to 112 species (35% world fauna) from all zoogeographical regions (except Madagascan) where Columbiformes occur. We measured the prevalence (IP) and the confidence interval (CI) for all infested host species. IP ranges between 4.2 and 66.7 (CI 0.2–100). We applied a bipartite analysis to determine host–parasite interaction, network indices, and host specificity on species and whole network levels. The Syringophilidae–Columbiformes network was composed of 25 mite species and 65 host species. The bipartite network was characterized by a high network level specialization H2′ = 0.93, high nestedness N = 0.908, connectance C = 0.90, and high modularity Q = 0.83, with 20 modules. Moreover, we reconstructed the phylogeny of the quill mites associated with columbiform birds on the generic level. Analysis shows two distinct clades: Meitingsunes + Psittaciphilus, and Peristerophila + Terratosyringophilus.

The family Syringophilidae (Acari: Prostigmata) includes obligatory ectoparasites, which occupy feather quills from various parts of avian plumage, where they feed and reproduce. Our study was concerned with the global fauna of syringophilid mites associated with Psittaciformes, as well as host-parasite specificity and evolution. We assumed that the system composed of quill mites and parrots represents a model group that can be used in a broader study of the relationships between parasites and hosts. In total, we examined 1524 host individuals of parrots belonging to 195 species, 73 genera, and 4 families (which constitute ca. 50% of global parrot fauna) from all zoogeographical regions where Psittaciformes occur. Among them, 89 individuals representing 81 species have been infested by quill mites belonging to 45 species and 8 genera. The prevalence of host infestations by syringophilid mites varied from 2.8% to 100% (95% confidence interval (CI Sterne method) = 0.1–100). We applied a bipartite analysis to determine the parasite-host interaction, network indices, and host specificity at the species and whole network levels. The Syringophilidae-Psittaciformes network was composed of 24 mite species and 47 host species. The bipartite network was characterized by a high network level specialization H2′ = 0.98, connectance C = 0.89, and high modularity Q = 0.90, with 23 modules, but low nestedness N = 0.0333. Moreover, we reconstructed the phylogeny of the quill mites on the generic level, and this analysis shows two distinct clades: Psittaciphilus (Peristerophila + Terratosyringophilus) (among Syringophilinae subfamily) and Lawrencipicobia (Pipicobia + Rafapicobia) (among Picobiinae). Finally, the distributions and host-parasite relationships in the system composed of syringophilid mites and parrots are discussed.

In this paper, we review the quill mite fauna of the family Syringophilidae Lavoipierre, 1953 (Acariformes: Prostigmata) associated with New World and African parrots (Aves: Psittaciformes: Psittacidae), and describe eight new species including: Neoaulobia unsoeldi Marciniak-Musial & Sikora sp. nov. from the Burrowing Parakeet Cyanoliseus patagonus in Argentina; Lawrencipicobia arini Marciniak-Musial & Sikora sp. nov. from the Black-headed Parrot Pionites melanocephalus in Surinam; L. ararauna Marciniak-Musial & Sikora sp. nov. from the Black-headed Parrot Ara ararauna in Brazil; L. touiti Marciniak-Musial & Sikora sp. nov. from the Golden-tailed Parrotlet Touit surdus in Brazil; Rafapicobia valdiviana Marciniak-Musial & Sikora sp. nov. from the Burrowing Parrot Cyanoliseus patagonus in Brazil; R. pyrrhura Marciniak-Musial & Sikora sp. nov. from the Green-cheeked Parakeet Pyrrhura molinae in Bolivia; R. xanthopterygius Marciniak-Musial & Sikora sp. nov. from the Blue-winged Parrotlet Forpus xanthopterygius in Brazil; and R. trainidadi Marciniak-Musial & Sikora sp. nov. from the Lilac-tailed Parrotlet Touit batavicus in Trinidad and Tobago. Additionally, we note fifteen new host species and many new locality records for the previously described taxa, and provide the keys for all species associated with psittaciform birds. Finally, we discuss the host-parasite relationships between syringophilid mites and parrots.

Hepatozoon spp. are apicomplexan parasites with a heteroxenous life cycles, involving vertebrate intermediate hosts and invertebrate definitive hosts. These parasites infect a wide variety of wild and domestic vertebrates causing subclinical infection or mild-to-severe clinical manifestations, depending on the parasite species and vertebrate host. Interestingly, each Hepatozoon spp. have a specific host range, suggesting a close host-parasite coevolutionary relationship. Hepatozoon sequences deposited between 2013 and 2023 were mined from GenBank to test which was the most employed marker for this parasite. We reconstructed the host and parasite phylogenies using 18S rDNA and cytB sequences, respectively. Subsequent analyses were stratified according to host vertebrate orders (Carnivora, Rodentia, and Squamata), and the corresponding sequences of their Hepatozoon parasites. Then, Procrustean Approach to Cophylogeny (PACo) and ParaFit were employed to assess their global cophylogenetic relationships. In addition, eMPRess was used to estimate the most probable co-evolutionary events, such as host switch, duplication, sorting, or cospeciation, accounting for the shared evolutionary history of Hepatozoon spp. and their vertebrate hosts. Global assessments of congruence between phylogenies of carnivore, rodent, and squamate hosts and those of their Hepatozoon parasites were significant (PACo: all m2XY < 0.655, all P < 0.001; ParaFit: all ParaFitGlobal Statistics < 72.992, all P < 0.007, all Procrustes R2 > 0.25), but not for the association between Hepatozoon spp. and invertebrates (PACo m2XY = 0.632, P < 0.001; ParaFitGlobal Statistic = 8.810, P = 0.124, R2 = 0.37). The most significant links occurred between Hepatozoon felis and felid hosts or Hepatozoon canis and canid hosts, but not between Hepatozoon americanum and domestic dogs or coyotes. Moreover, eMPRess showed that the coevolutionary history between Hepatozoon spp. and vertebrate host phylogenies was mainly explained by host switching and less frequently by cospeciation events. These findings highlight the ability of Hepatozoon spp. associated to certain vertebrate orders to infect those with a close phylogenetic relationship. This in turn helps to understand how hepatozoonosis can emerge in susceptible hosts within specific geographical areas by spillover events.

BackgroundPrevious studies have shown that haemosporidian parasites (Haemoproteus (Parahaemoproteus) and Plasmodium) infecting passerine birds have an evolutionary history of host switching with little cospeciation, in particular at low taxonomic levels (e.g., below the family level), which is suggested as the main speciation mechanism of this group of parasites. Recent studies have characterized diverse clades of haemosporidian parasites (H. (Haemoproteus) and H. (Parahaemoproteus)) infecting non-passerine birds (e.g., Columbiformes, Pelecaniiformes). Here, we explore the cospeciation history of H. (Haemoproteus) and H. (Parahaemoproteus) parasites with their non-passerine hosts.MethodsWe sequenced the mtDNA cyt b gene of both haemosporidian parasites and their avian non-passerine hosts. We built Bayesian phylogenetic hypotheses and created concensus phylograms that were subsequently used to conduct cospeciation analyses. We used both a global cospeciation test, PACo, and an event-cost algorithm implemented in CoRe-PA.ResultsThe global test suggests that H. (Haemoproteus) and H. (Parahaemoproteus) parasites have a diversification history dominated by cospeciation events particularly at the family level. Host-parasite links from the PACo analysis show that host switching events are common within families (i.e., among genera and among species within genera), and occasionally across different orders (e.g., Columbiformes to Pelecaniiformes). Event-cost analyses show that haemosporidian coevolutionary history is dominated by host switching and some codivergence, but with duplication events also present. Genetic lineages unique to raptor species (e.g., FALC11) commonly switch between Falconiformes and Strigiformes.ConclusionsOur results corroborate previous findings that have detected a global cospeciation signal at the family taxonomic level, and they also support a history of frequent switching closer to the tips of the host phylogeny, which seems to be the main diversification mechanism of haemosporidians. Such dynamic host-parasite associations are relevant to the epidemiology of emerging diseases because low parasite host specificity is a prerequisite for the emergence of novel diseases. The evidence on host distributions suggests that haemosporidian parasites have the potential to rapidly develop novel host-associations. This pattern has also been recorded in fish-monogenean interactions, suggesting a general diversification mechanism for parasites when host choice is not restricted by ecological barriers.

Curvularia species exhibit a wide range of ecological roles, including plant, animal, or human pathogens, as well as epiphytes, saprophytes, or endophytes, predominantly associated with cultivated cereals. In this study, several fungal isolates with similar characteristics in the genus Curvularia were recovered from various poaceous hosts (Poales plants) in different locations in Iran during 2012‒2022. Based on the morphological characteristics and multilocus phylogeny of the translation elongation factor-1 alpha (TEF1), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and the internal transcribed spacer (ITS-rDNA) genes, the studied isolates were assigned to five species, of which Curvularia caspica, sp. nov. and C. cyperi, sp. nov. are introduced as novel species and Curvularia nodulosa and C. oryzae are new records for Iran’s mycobiota. Molecular studies revealed a closer relationship between one of the studied species (Curvularia sp.) and C. frankliniae. However, due to the absence of detailed morphological characteristics for C. frankliniae, morphological comparisons were not feasible. To precisely establish their phylogenetic position, more isolates need to be analyzed. Consequently, the studied species was identified as Curvularia sp. in this study. Additionally, a new clade, “papendorfii,” was established to accommodate 11 species that share common morphological characteristics and form a distinct clade in phylogenetic analyses. The morphology, habitat, distribution, and evolutionary relationships of each species with other Curvularia species were analyzed, accompanied by detailed illustrations and descriptions. This comprehensive study offers valuable insights into the diversity and distribution of Curvularia species, enhancing our understanding of fungal ecology and taxonomy.

Cerasus subhirtella (Miq.) Sok. is a widely used ornamental tree in urban areas around China and has a high ornamental value. From 2018 to 2020, a root rot disease was observed in C. subhirtella in Meitan County, Weng'an County, and Guiyang city of Guizhou, China (106.71 E, 26.57 N). Diseased C. subhirtella trees exhibited wilting with leaf chlorosis accompanied by brown to black root discoloration. In an area of 100 ha in total, with disease incidence ranging from 60 to 80%. Six symptomatic plants with root rot were randomly collected from three locations where disease symptoms were observed for pathogen isolation. Fifty fragments of diseased roots (5×5mm) were disinfected in 3% sodium hypochlorite for 30 s and 75% alcohol for 60 s, rinsed three times in sterile distilled water, plated on potato dextrose agar (PDA; BoWei, Shanghai), and incubated at 28 °C in the dark for 7 days. Eighteen isolates were purified by single spore culturing. Typical Fusarium spp. colonies were obtained from all root samples. On PDA, the colonies showed white and the hyphae were dense, while the colony of isolate YH15 showed pale yellow on the back, radial growth and produced chlamydospores. The macrospores (YH15) were straight to subarcuate, measured 15.3 to 25.1 × 2.5 to 6.2 μm (n=50). The microconidia (YH26) were ellipsoid to ovoid, measured 8.6 to 12.7 × 1.6 to 5.1 μm (n=50). These morphological characteristics were consistent with Fusarium spp., as described recently in Vitullo et al. (2014). To confirm the morphological diagnosis, genomic DNA from the isolates was extracted. The internal transcribed spacer (ITS) (White et al, 1990) region of rDNA and a β-tubulin (Varga et al, 2011) gene fragment were amplified with the primers ITS1/ITS4 and Bt2a/Bt2b, respectively, and were subsequently sequenced. Maximum likelihood analysis was carried out using MEGA 11.0. BLAST analysis revealed that the ITS and β-tubulin sequences of isolate YH15 were 100% homologous with F. oxysporum, and the isolate YH26 had a 99.69~100% homology with F. solani. Sequences of isolate YH15 and YH26 were deposited in GenBank (ITS: OQ363005 and OQ363049; β-tubulin: OQ398187 and OQ398180). The isolate YH15 was thus identified as F. oxysporum by the morphological characteristics and sequences analysis, and the isolate YH26 was identified as F. solani. A reconstructed phylogenetic tree also confirmed their phylogenetic position. The healthy 2-year-old C. subhirtella plants grown in autoclaved acid yellow soil were used for the pathogenicity tests. Then, 50 mL of conidial suspension (2.0×105 conidia/mL, in medium) of 7-day-old isolates YH15 and YH26 were gently applied to the soil in each of the 10 pots as the treatment. A sterilized fungal culture matrix (PDB; BoWei, Shanghai) was applied to each of 10 pots as a control. All pots (30 cm high, 25 cm upper diameter, 15 cm base diameter) were placed in a greenhouse (25 °C, 12 h photoperiod). After 30 days of inoculation, all plants inoculated with the isolates showed wilting symptoms, and the roots showed light-brown to dark-brown lesions. No symptoms were observed in the controls. The pathogen was reisolated from all symptomatic roots and identified as F. oxysporum and F. solani as described above. The pathogenicity test was repeated twice with similar results. Although this fungus was previously reported to cause root disease in many hosts (Li et al., 2020; Gibert et al., 2022), this is the first report of F. oxysporum and F. solani causing root rot in C. subhirtella in China.

Tetragonula laeviceps sensu lato (s.l.) Smith 1857 has the most complicated nomenclatural history among the Tetragonula genera. The objective of this study was to investigate whether T. laeviceps s.l. individuals with worker bees are grouped in the same or nearly the same morphological characteristics and have similar COI haplotype cluster groups. A total of 147 worker bees of T. laeviceps s.l. were collected from six sampling sites in Sabah (RDC, Tuaran, Kota Marudu, Putatan, Kinarut and Faculty of Sustainable Agriculture (FSA)), but only 36 were selected for further studies. These specimens were first classified according to the most obvious morphological characteristics, i.e., hind tibia color, hind basitarsus color and body size. Group identification was based on morphological characteristics important for distinguishing the four groups within T. laeviceps s.l. The four groups of T. laeviceps s.l. had significantly different body trait measurements for the TL (total length), HW (head width), HL (head length), CEL (compound eye length), CEW (compound eye width), FWLT (forewing length, including tegula), FWW (forewing width), FWL (forewing length), ML (mesoscutum length), MW (mesoscutum width), SW (mesoscutellum width), SL (mesoscutellum length), HTL = (hind tibia length), HTW (hind tibia width), HBL (hind basitarsus length) and HBW (hind basitarsus width) (p < 0.001). Body color included HC (head color), CC (clypeus color), ASC (antennae scape color), CFPP (Clypeus and frons plumose pubescence), HTC (hind tibia color), BSC (basitarsus color), SP (leg setae pubescence), SP (Thorax mesoscutellum pubescence), SPL (thorax mesoscutellum pubescence length) and TC (thorax color) (p < 0.05). The most distinctive features of the morphological and morphometric characteristics measured by PCA and LDA biplot that distinguish Group 1 (TL6-1, TL6-2 and TL6-3) from the other groups were the yellowish-brown ASC and the dark brown TC. Group 2 (haplotypes TL2-1, TL2-2 and TL2-3 and TL4-1, TL4-2 and TL4-3) had a dark brown ASC and a black TC, while Group 3 (haplotypes TL11-1, TL11-2 and TL11-3) had a blackish-brown ASC, a black TC and the largest TL, FWW and FWL. As for phylogenetic relationships, 12 out of 36 haplotypes showed clear separation with good bootstrap values (97-100%). The rest of the haplotypes did not show clear differentiation between subclades that belonged together, regardless of their morphology and morphometric characteristics. This suggests that the combination of DNA barcoding for species identification and phylogenetic analysis, as well as traditional methods based on morphological grouping by body size and body color, can be reliably used to determine intraspecific variations within T. laeviceps s.l.

Discordant phylogenies suggest repeated host shifts in the Fusarium–Euwallacea ambrosia beetle mutualism

External morphological characters were used to reconstruct a phylogeny of the mite family Syringophilidae (Acariformes: Cheyletoidea), which are permanent parasites inhabiting the quills of bird feathers. A total of 53 syringophilid genera and 79 charac- ters were included in the data matrix; maximum parsimony (MP) and Bayesian analyses (BA) were performed to determine their phylogenetic relationships. The consensus of unweighted MP trees was weakly resolved. Only four generic groups were recognized: Aulonastus + Krantziaulonastus (i) and (Creagonycha + Kethleyana) + (Megasyringophilus + Selenonycha) (ii) - both with low Bremer support (BS 1); the subfamily Picobiinae - Picobia, Calamincola, Columbiphilus (Neopicobia + Rafapicobia) (BS 12) (iii) and Psittaciphilus generic group - (Meitingsunes + Psittaciphilus) (Peristerophila + (Neoperisterophila + (Castosyringophilus + Terratosyringophilus))) (BS 2) (iv). BA revealed a consensus tree with a topology similar to MP. The two main groups recognized by MP, the subfamily Picobiinae and Psittaciphilus, both received the highest support of 1; while two other groups recognized by MP - Aulonastus + Krantziaulonastus and (Creagonycha + Kethleyana) + (Megasyringophilus + Selenonycha) received relatively low support of 0.73-74 and 0.76-77, respectively. The consensus of re-weighted MP trees was almost fully resolved but, the majority of the generic groups, excluding the Picobiinae and Psittaciphilus were supported by just a few non-unique synapomorphies with a high probability of homoplastic origin. The most intriguing result is the paraphyly of the Syringophilinae in respect to picobii- nes. The pattern of the re-weighted tree demonstrates only patches of parallel evolution at the level of syringophilid genera and bird orders. Perhaps horizontal shifts on phylogenetically distant hosts and colonization of quill (calamus) types other than primaries and secondaries were also important in the evolution of the syringophilids.

2009년 11월에 서귀포에서 꽃댕강나무 흰가루병을 발견하였다. 이어 제주, 부산, 통영 등 남부지방에서도 추가적으로 발견되었다. 흰색의 균체가 잎, 어린 줄기, 꽃을 감염하여 관상가치를 떨어뜨렸으며, 발병이 지속되면 잎 앞면의 병환부는 적자색으로 변하였다. 이 흰가루병균의 형태적 특징과 분자적 분석을 통하여 이 곰팡이는 Erysiphe abeliicola U. Braun & S. Takam.로 동정되었다. 무성세대의 분류학적 특징은 이 연구를 통하여 처음으로 기재되는데, 균사의 굴곡형 부착기와 분생포자경의 짧은 기부세포가 특징적이었다. 성숙한 자낭구의 분류학적 특징은 앞선 일본의 기재와 거의 일치하였다. 우리나라 시료에서 rDNA ITS 영역의 염기서열을 처음으로 분석하여 이 종이 Erysiphe속의 Microsphaera절에 속함을 밝혔으며, 이는 형태적 특징과 상응하는 결과였다. 이로써 우리나라에서 E. abeliicola에 의한 꽃댕강나무 흰가루병을 처음으로 보고하고, 꽃댕강나무가 이 흰가루병균의 기주로 확인된 것은 세계적으로 처음이다. In November 2009, a powdery mildew on glossy abelia (Abelia <TEX>${\times}$</TEX> grandiflora) was found in Seogwipo, Jeju Island, Korea. Further survey in the southern part of Korea, e.g., Jeju, Busan, and Tongyeong confirmed occurrence of the disease. White colonies were present on leaves, young stems, and flowers, detracting from their beauty in landscape plantings. Severely infected lesions were discolored to red-purplish. Based on the morphological characteristics and analysis of rDNA, the fungus associated with the symptoms was identified as Erysiphe abeliicola U. Braun & S. Takam. This work provides the morphological feature of its anamorph for the first time, which is characterized by having multi-lobed hyphal appressoria and short foot-cells of conidiophores. Morphological characteristics of mature chasmothecia were consistent with the previous Japanese record of this species. The sequence of internal transcribed spacer region of ribosomal DNA obtained from a Korean sample showed that this species places in the section Microsphaera of the genus Erysiphe in phylogenetic position, corresponding with the classical taxonomy. This is the first report of E. abeliicola and its host plant in Korea. The host plant A. <TEX>${\times}$</TEX> grandiflora is newly listed in the host range of E. abeliicola.

Kitagawia Pimenov is one of the segregate genera of Peucedanum sensu lato within the Apiaceae. The phylogenetic position and morphological delimitation of Kitagawia have been controversial. In this study, we used plastid genome (plastome) and nuclear ribosomal DNA (nrDNA) sequences to reconstruct the phylogeny of Kitagawia, along with comparative plastome and morphological analyses between Kitagawia and related taxa. The phylogenetic results identified that all examined Kitagawia species were divided into Subclade I and Subclade II within the tribe Selineae, and they were all distant from the representative members of Peucedanum sensu stricto. The plastomes of Kitagawia and related taxa showed visible differences in the LSC/IRa junction (JLA) and several hypervariable regions, which separated Subclade I and Subclade II from other taxa. Fruit anatomical and micromorphological characteristics, as well as general morphological characteristics, distinguished the four Kitagawia species within Subclade I from Subclade II and other related genera. This study supported the separation of Kitagawia from Peucedanum sensu lato, confirmed that Kitagawia belongs to Selineae, and two species (K. praeruptora and K. formosana) within Subclade II should be placed in a new genus. We believe that the "core" Kitagawia should be limited to Subclade I, and this genus can be distinguished by the association of a series of morphological characteristics. Overall, our study provides new insights into the phylogeny, plastome evolution, and taxonomy of Kitagawia.