The freshwater cyanobacterium Raphidiopsis raciborskii is an invasive species that was originally described as tropical and is now widely distributed in temperate regions. The current taxonomic position was established based on a multilevel approach with the morphological description of natural populations as well as their ultrastructural, physiological and molecular characterization. The practical problem in identifying this species is that the morphology of the trichome in the natural environment can vary considerably during population growth. The aim of this study was to investigate the morphological variability of R. raciborskii during its blooming in a temperate floodplain lake on the Middle Danube (Europe). In both cases, only straight trichomes were found. Young trichomes with one or two acuminate ends and without heterocytes, referred to as primary filaments, can be exclusively monodominant at the beginning of bloom formation and remain dominant throughout the year, leading to taxonomic confusion. In mature populations, the different morphological forms of secondary filaments may differ in the size of the filaments and in the number and size of akinetes and heterocytes formed in the trichomes. The correct taxonomic identification and early detection of R. raciborskii in natural freshwaters is extremely important for the successful control of the spread of this potentially toxic species.

Two new European species in Medetera (Diptera: Dolichopodidae) are described here. Medetera demirae sp. nov.—named after the Flemish minister for Justice and Enforcement, Environment, Energy and Tourism (2019–2024)—has been discovered at three localities in the eastern province of Limburg (Flanders, Belgium) and is thus far only known from this area. It can be easily recognized by a dentate hypandrium and phallus, a unique character not found in any other known Medetera species. M. nigrohalteralis sp. nov. had long been regarded as Medetera takagii Negrobov, 1970 by European dolichopodid workers but ultimately proved to represent a separate species. This species seems widespread in northwestern and central Europe. Morphologically, it is very similar to M. takagii and M. tristis (Zetterstedt, 1838) and shares an infuscate halter with both species. It differs from both by the shape of its hypandrium and surstylus. M. demirae sp. nov., large numbers of M. nigrohalteralis sp. nov., and other rarely seen Medetera species were collected in Belgium using a new type of tree trunk eclector. A widespread application of this trap might considerably change our view on the occurrence and rarity of tree trunk-dwelling invertebrates.

This study addresses a critical issue in plant taxonomy and phylogeny: the relationship between archaeological materials and potentially analogous living populations. Given the current limitations in definitively establishing the identity between archaeological and contemporary materials, we propose an intermediate approach. This approach serves as a useful framework while scientific methods advance towards definitively assessing whether an archaeological wheat sample, approximately 5000 years old from Central Europe, belongs to the same species as a modern wheat currently endemic to Central Asia. This approach consolidates the taxonomic validity of both archaeological and living materials, allowing them to be treated as distinct taxa while preserving the possibility of future identification convergence. Triticum vulgare var. antiquorum, an archaeobotanical small-grained, free-threshing wheat, was originally described in 1865. The 1982 discovery of morphologically similar living wheat in Tajikistan raised questions about their taxonomic relationship. Our study reviews the nomenclature of both taxa, designating an illustration from the original description of T. vulgare var. antiquorum as the lectotype to align with the traditional concept of the name. We address the ambiguity surrounding “Triticum antiquorum” as used by Russian agronomists and botanists, proposing a more precise circumscription within the current systematic framework of the genus based on cytogenetic data. Consequently, we describe a new taxon, Triticum sphaerococcum subsp. antiquorum. The holotype, selected from material with available cytogenetic data and grown from Professor Udachin’s original Pamir (Tajikistan) collection, is preserved in the N.I. Vavilov All-Russian Institute of Plant Genetic Resources (WIR) collection. It is deposited at the I.M. Krasnoborov Herbarium of Central Siberian Botanical Garden SB RAS (NS), with an isotype at the WIR. This taxonomic revision and new subspecies designation provide a robust framework for reconciling archaeological and contemporary wheat diversity, advancing our understanding of wheat evolution and agricultural history.

Recently, based on light microscopy images, the tubercle structure on the seed surface of 100 Silene species was quantitatively described, including tubercle width, height, and curvature associated with general morphometric data. Curvature measures the rate of change of the tangent vector in a curve and can be calculated by the following methods described for Arabidopsis roots. Here, we apply curvature measurements to the SEM images of 40 Silene species from Türkiye, demonstrating that a quantitative analysis of tubercles can be made based on SEM images with similar results to optical photographs. The association of morphometric tubercle data allows for classification into six groups, five of them corresponding to described shapes: rugose (two groups), echinate, mammillate, and papillose, and a sixth group of tubercles plane on top. The curvature values vary between 20 and 200 mm−1 and differ among the morphological tubercle types described. The correlation of curvature values with other general measurements and morphological seed characteristics is investigated. Tubercle quantification not only is a useful tool for Silene taxonomy, but also provides the basis for the analysis of the genetic control and developmental effects on tubercle structure and shape in the seed surface.

Miroculis (Ommaethus) Savage and Peters, 1983 (Ephemeroptera, Leptophlebiidae) is reviewed based on fresh material from Southeastern Brazil and on type specimens. Miroculis (Ommaethus) cipoensis sp. n. is described based on male and female imagos from Serra do Cipó, Minas Gerais State, Brazil. It can be distinguished from other species of the subgenus based on the following characteristics: forewings with membrane brown and dark brown mark around cross veins; hind wing uniformly brown; forceps segment I light brown, segment II and III lighter; penis lobe long (at least ⅔ of forceps segment I) and apically rounded and curved on apical ¼; length of body between 5.0 and 6.3 mm. Photographs of fresh material belonging to M. (O.) froehlichi Savage and Peters, 1983 and M. (O.) mourei Savage and Peters, 1983 are provided, clarifying the boundaries between the existing species of the subgenus. Based on that, M. (O.) misionensis Domínguez, 2007 is considered a junior synonym of M. (O.) mourei. A key to the male imagos of the subgenus is presented, as well as a distributional map with updated records of the species.

The Ilyarachninae are a diverse and widely distributed subfamily of the asellote family Munnopsidae. This paper describes nine new deep-sea species from two Ilyarachninae genera, Ilyarachna and Notoapais, from the southwestern Pacific, namely from New Zealand and the east coast of Australia. Ilyarachna aculeatus n. sp., Ilyarachna brucei n. sp., Ilyarachna franki n. sp., Ilyarachna mclayi n. sp., Ilyarachna pacifica n. sp., Ilyarachna sami n. sp., Ilyarachna taranui n. sp. and Notopais chathamensis n. sp. are described from New Zealand waters, while Notopais likros n. sp. is described from off the east coast of Australia. Additionally, a redescription of Notopais spinosa from the Balleny Islands, Antarctica, and a revised key to the Ilyarachna and Notopais species from the southwest Pacific are included, and the distribution, affinities, and diagnostic characters of the new species are discussed.

The long-horn bee genus Tetralonia consists of 35 Western Palaearctic species that are associated mostly with the family Asteraceae as host plants. A minority of the species are, however, exclusively associated with other host plants that have particularly large pollen grains, such as those in the plant families Caprifoliaceae, Malvaceae, and Onagraceae. This work presents a taxonomic account and morphological description of the assemblages of Tetralonia species with atypical (non-Asteraceae) host plants. It includes a key to the pollinosa-group, which contains most of the species, a description of three regionally restricted new species, namely T. eoacinctella Dorchin sp. nov., T. epilobii Dorchin sp. nov., and T. stellipilis Dorchin sp. nov., a lectotype designation for Eucera cinctella Saunders, 1908 [=Tetralonia cinctella (Saunders, 1908)], and a neotype designation for Apis malvae Rossi, 1790 [=Tetralonia malvae (Rossi, 1790)]. In addition, the name Eucera macroglossa Illiger, 1806 is confirmed as a synonym of Apis malvae Rossi, 1790; Tetralonia macroglossa ssp. xanthopyga Alfken, 1936 is officially placed in synonymy with Apis malvae Rossi, 1790; and Macrocera confusa Pérez, 1902 is listed as a doubtful synonym of Tetralonia scabiosae Mocsàry, 1879 (syn. nov.).

The turn of the year is a good opportunity to reflect on the past year and summarize the milestones [...]

Amana, commonly known as ‘East Asian tulips’, has recently been found to harbor cryptic diversity due to recent field work and systematic investigations. In this study, we included 64 populations from all 12 Amana species and performed microscopic observations of their epidermal morphology. The leaf epidermis stomatal distribution of Amana can be characterized into three types: dense stomata (>10/per view or 263/mm2), sparse stomata (<10/per view or 263/mm2), and stomata absent. The epidermal cells of Amana can be characterized into four types: rectangular, long rectangular, nearly rectangular, and rhombic. The anticlinal wall morphology of the epidermal cells can be characterized into three types: linear, wavy, and nearly linear with mixed shallow waves. All the results were helpful for classification of Amana species. According to the reconstruction of ancestral characters analyses, the common ancestor of Amana is most likely to have leaves with dense stomata on both sides, and epidermal cells that have linear vertical walls.

The new anchovy Stolephorus horizon n. sp., described on the basis of 34 specimens collected from Fiji and Tonga, has been previously confused with Stolephorus indicus (van Hasselt, 1823) or Stolephorus scitulus (Fowler, 1911). However, the new species differs from both of the latter in having the pectoral fin without melanophores, and a unique range of gill rakers. A redescription of S. scitulus and an identification key of species previously identified as S. indicus are also provided.