Background: The proper identification of feather grasses in nature is often limited due to phenotypic variability and high morphological similarity between many species. Among plausible factors influencing this issue are hybridisation and introgression recently detected in the genus. Nonetheless, to date, only a bounded set of taxa have been investigated using integrative taxonomy combining morphological and molecular data. Here, we report the first large-scale study on five feather grass species across several hybrid zones in Russia and Central Asia. In total, 302 specimens were sampled in the field and classified based on the current descriptions of these taxa. They were then genotyped with high density genome-wide markers and measured based on a set of morphological characters to delimitate species and assess levels of hybridisation and introgression. Moreover, we tested species for past introgression and estimated divergence times between them.Results: Our findings demonstrated that 250 specimens represent five distinct species:S. baicalensis,S. capillata,S. glareosa,S. grandisandS. krylovii. The remaining 52 individuals provided evidence for extensive hybridisation betweenS. capillataandS. baicalensis,S. capillataandS. krylovii,S. baicalensisandS. krylovii, as well as to a lesser extent betweenS. grandisandS. krylovii,S. grandisandS. baicalensis. We detected past reticulation events betweenS. baicalensis,S. krylovii,S. grandisand inferred that diversification within speciesS. capillata,S. baicalensis,S. kryloviiandS. grandisstarted ca. 130–96 kya. In addition, the assessment of genetic population structure revealed signs of contemporary gene flow between populations across species from the sectionLeiostipa, despite significant geographical distances between some of them. Lastly, we concluded that only 5 out of 52 hybrid taxa were properly identified solely based on morphology.Conclusions: Our results support the hypothesis that hybridisation is an important mechanism driving evolution inStipa. As an outcome, this phenomenon complicates identification of hybrid taxa in the field using morphological characters alone. Thus, integrative taxonomy seems to be the only reliable way to properly resolve the phylogenetic issue ofStipa. Moreover, we believe that feather grasses may be a suitable genus to study hybridisation and introgression events in nature.

Hybridisation in the wild between closely related species is a common mechanism of speciation in the plant kingdom and, in particular, in the grass family. Here we explore the potential for natural hybridisation inStipa(one of the largest genera in Poaceae) between genetically distant species at their distribution edges in Mountains of Central Asia using integrative taxonomy. Our research highlights the applicability of classical morphological and genome reduction approaches in studies on wild plant species. The obtained results revealed a new nothospecies,Stipa × lazkovii, which exhibits intermediate characters toS. kryloviiandS. bungeana. A high-density DArTseq assay disclosed thatS. × lazkoviiis an F1 hybrid, and established that the plastid and mitochondrial DNA was inherited fromS. bungeana. In addition, molecular markers detected a hybridisation event between morphologically and genetically distant speciesS. bungeanaand probablyS. glareosa. Moreover, our findings demonstrated an uncertainty on the taxonomic status ofS. bungeanathat currently belongs to the sectionLeiostipa, but it is genetically closer toS. breviflorafrom the sectionBarbatae. Finally, we noticed a discrepancy between the current molecular data with the previous findings onS. capillataandS. sareptana.

Festuca is one of the largest genera within the Poaceae family. Molecular phylogenies demonstrate that Festuca s.l. comprises two groups: broad‐ and fine‐leaved species. The latter is the species‐richest and taxonomically complicated group due to being paraphyletic. Here, we provide the first insight into the phylogeny of 17 fine‐leaved species of Altai fescues. Based on genome‐wide genotyping, the examined taxa were divided into three markedly differentiated clusters. The first cluster comprises species from the F. rubra complex, the second cluster includes the F. brachyphylla complex, and the third cluster contains taxa from the groups F. ovina, F. valesiaca, and F. kryloviana. Importantly, we detected a complex genetic pattern within the groups of F. valesiaca and F. kryloviana. Moreover, our findings underline a discrepancy between morphological and molecular data for some species distributed within the Altai Mountain Country. We suggest that in order to validate the current findings on the fine‐leaved fescues, additional comprehensive research including morphological, karyological, and molecular methods is required. Nonetheless, our work provides a baseline for further investigations on the genus and studies on the floral diversity of Asia.

The Eurasian plant Stipa capillata is the most widespread species within feather grasses. Many taxa of the genus are dominants in steppe plant communities and can be used for their classification and in studies related to climate change. Moreover, some species are of economic importance mainly as fodder plants and can be used for soil remediation processes. Although large-scale molecular data has begun to appear, there is still no complete or draft genome for any Stipa species. Thus, here we present a single-molecule long-read sequencing dataset generated using the Pacific Biosciences Sequel System. A draft genome of about 1004 Mb was obtained with a contig N50 length of 351 kb. Importantly, here we report 81,224 annotated protein-coding genes, present 77,614 perfect and 58 unique imperfect SSRs, reveal the putative allopolyploid nature of S. capillata, investigate the evolutionary history of the genus, demonstrate structural heteroplasmy of the chloroplast genome and announce for the first time the mitochondrial genome in Stipa. The assembled nuclear, mitochondrial and chloroplast genomes provide a significant source of genetic data for further works on phylogeny, hybridisation and population studies within Stipa and the grass family Poaceae.

The Eragrostis pilosa complex (Poaceae) comprises five widely distributed and regionally invasive species—E. albensis, E. amurensis, E. imberbis, E. multicaulis, and E. pilosa, distinguished by tiny and variable morphological characters and with so far unknown phylogenetic relationships. Recently, some doubts have been raised about the status of an invasive glandular morphotype occurring in Central Europe assigned either to E. amurensis or to E. albensis. Here, we addressed this issue by analysing morphology, internal transcribed spacers of nuclear ribosomal DNA, and five inter-simple sequence repeat markers. The genetic evidence supported closer relationship of this glandular morphotype to eglandular E. albensis, widely established in Central Europe, than to glandular E. amurensis described from Asia. We propose to adopt a new taxonomic treatment that E. albensis includes both eglandular and glandular individuals, and to classify the glandular ones as E. albensis var. scholziana M. Nobis & A. Wróbel var. nova. Currently this new taxon is known from a dozen of localities in Central Europe and is invasive in the lower section of the Oder River valley, whereas Eragrostis albensis var. albensis has already spread widely across Europe in riparian phytocenoses and anthropogenic habitats. Since probably the first registered records in 1940s, it has been observed in European part of Russia, Belarus, Ukraine, Poland, Slovakia, Czech Republic, Germany, Austria, the Netherlands, and its further invasion is likely to proceed. We provided distribution maps concerning spread dynamics of E. albensis in Europe from 1947 to 2020. In total, the species has been observed on over 1300 localities so far, most of which were found after 2000.