Solveig Bua Løken

• Mjøen, Hedvig Elisabeth; Løken, Solveig Bua; Carlsen, Tor; Brysting, Anne Krag & Bjorå, Charlotte Sletten (2026). Resolving the Veratrum phylogeny in northern Fennoscandia by targeted sequencing. Taxon. ISSN 0040-0262. 75(4). doi: 10.1002/tax.70201. Full text in Research Archive Show summary

  The genus Veratrum comprises approximately 24 species from temperate and arctic North America and Eurasia. In Europe, Veratrum is mainly distributed in mountainous areas of central and southern Europe but is also locally abundant in coastal areas of north-eastern Finnmark, Norway. The taxon name for the Veratrum in Finnmark has over the years been disputed. Several names have been applied, including V. album, V. lobelianum, and various subspecies of these. Previous phylogenetic analyses of Veratrum based on Sanger sequences of the ITS region have lacked sufficient resolution to resolve the relationships within the genus. Furthermore, the Veratrum in Finnmark has not been included in any molecular phylogenetic analysis, leaving its relationship to other populations of Veratrum unknown. The aims of this study were therefore to place the Veratrum in Finnmark in a molecular phylogenetic context, assess if this group represents a separate taxon, and determine the appropriate nomenclature. We applied a target capture approach, using the Angiosperms-353 probe set, to obtain a multi-locus phylogenetic dataset. Our phylogeny reveals that the Veratrum in Finnmark are closely related to Veratrum populations in northern Finland and Russia. Northern European Veratrum resolves as a distinct clade and represents a distinct taxon separate from populations in central Europe. We propose the name V. album subsp. misae for the northern European Veratrum.

• Kitur, Abigael Jepkosgei; Stedje, Brita; Wabuyele, Emily & Løken, Solveig Bua (2025). Exploring the phylogenomics of Dipcadi (Asparagaceae, Scilloideae) and assessing the utility of ITS as a DNA barcode. Plant Systematics and Evolution. ISSN 0378-2697. 311(3). doi: 10.1007/s00606-025-01947-0. Full text in Research Archive Show summary

  Dipcadi (Asparagaceae, Scilloideae) has long presented phylogenetic and taxonomic challenges. A recent study by Chapano et al. (in press) based on ITS sequence data found several non-monophyletic species and an unresolved backbone topology of the genus. In this study, we present the first high-throughput sequencing (HTS) phylogeny of Dipcadi, using data from target capture of the angiosperms353 loci. The sampling is focused on African diversity. Additionally, we provide an updated ITS phylogeny representing 15 Dipcadi species, including 18 newly sequenced accessions. We expand taxon sampling, especially of D. longifolium, to further explore phylogenetic relationships and species limits in the genus. Although the angiosperms353 loci did not fully resolve the backbone topology of Dipcadi, both approaches generated similar topologies with six well-supported clades, but with incongruences regarding deep nodes. We corroborate monophyly of D. marlothii and D. glaucum. Dipcadi longifolium represents a species complex, possibly including D. gracillimum, but we refrain from taxonomic revisions based on the current sampling. Dipcadi viride and possibly D. platyphyllum are paraphyletic, warranting further attention. Our findings confirm that ITS can be effectively employed as a barcode marker in Dipcadi.

• Skrede, Inger; Løken, Solveig Bua; Mathiesen, Cecilie & Schumacher, Trond Kristian (2023). Additions to the knowledge of the genus Helvella in Europe. New records and de novo description of five species from the Nordic region. Fungal Systematics and Evolution. 11, p. 71–84. doi: 10.3114/fuse.2023.11.06. Full text in Research Archive Show summary

  Helvella is a species-rich genus, forming a large variation of astounding ascocarps in many different habitats. During the last decade, molecular markers and morphological characters have been combined to delimit and identify cryptic species in this genus. We report on a list of 54 species of Helvella s.s. in the Nordic region and describe five new species, i.e. H. bresadolae , H. convexa , H. japonica , H. nordlandica and H. oroarctica . The morphological and molecular characteristics of the new species and the emended / hypocrateriformis, / fibrosa-macropus, and / fallaxpezizoides lineages of Helvella s.s. are shortly commented upon. Further we include a discussion of the distribution of species in the Nordic region based on a large set of studied collections. The ecological versatility and variable geographic patterns of these species indicate that cryptic species may have contrasting ecology in their local habitats.

• Løken, Solveig Bua; Skrede, Inger & Schumacher, Trond (2019). The Helvella corium species aggregate in Nordic countries - Phylogeny and species delimitation. Fungal Systematics and Evolution. 5, p. 169–186. doi: 10.3114/fuse.2020.05.13. Full text in Research Archive Show summary

  Mycologists have always been curious about the elaborate morphotypes and shapes of species of the genus Helvella. The small, black, cupulate Helvella specimens have mostly been assigned to Helvella corium, a broadly defined morpho-species. Recent phylogenetic analyses, however, have revealed an aggregate of species hidden under this name. We performed a multispecies coalescent analysis to re-assess species limits and evolutionary relationships of the Helvella corium species aggregate in the Nordic countries. To achieve this, we used morphology and phylogenetic evidence from five loci – heat shock protein 90 (hsp), translation elongation factor 1-alpha (tef), RNA polymerase II (rpb2), and the 5.8S and large subunit (LSU) of the nuclear ribosomal DNA. All specimens under the name Helvella corium in the larger university fungaria of Norway, Sweden and Denmark were examined and barcoded, using partial hsp and/or rpb2 as the preferential secondary barcodes in Helvella. Additional fresh specimens were collected in three years (2015–2018) to obtain in vivo morphological data to aid in species discrimination. The H. corium species aggregate consists of seven phylogenetically distinct species, nested in three divergent lineages, i.e. H. corium, H. alpina and H. pseudoalpina sp. nov. in the /alpina-corium lineage, H. alpestris, H. macrosperma and H. nannfeldtii in the /alpestris-nannfeldtii lineage, and H. alpicola as a weakly supported sister to the /alpestris-nannfeldtii lineage. Among the seven species, the ribosomal loci expressed substantial variation in evolutionary rates, suggesting care in the use of these regions alone in delimitation of Helvella species. Altogether, 469 out of 496 available fungarium specimens were successfully barcoded.

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• Vestre, Katharina; Vestre, Linnea; Løken, Solveig Bua; Støstad, Hanna Nyborg & Nagel, Lisa Marie (2023). Naturens rekordbok. Aschehoug & Co. ISBN 9788203399695. 104 p. Full text in Research Archive

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• Løken, Solveig Bua; Bendiksby, Mika & Stedje, Brita (2022). A HTS approach for delimiting taxa of Drimiopsis, Ledebouria and Resnova (Asparagaceae, subfamily Scilloidea). Full text in Research Archive
• Ballesteros, Jesus Adrian Chimal & Løken, Solveig Bua (2022). En doktorgrad i pandemi. [Internet]. Online. Full text in Research Archive
• Løken, Solveig Bua; Bendiksby, Mika & Stedje, Brita (2020). Phylogeny, character state evolution and species delimitation in Drimiopsis, Ledebouria and Resnova (Asparagaceae, subfamily Scilloidea). Full text in Research Archive
• Løken, Solveig Bua; Bendiksby, Mika & Stedje, Brita (2019). LEDEBOURIA & FRIENDS - Phylogeny, character state evolution and species delimitation in three African monocot genera: Drimiopsis, Ledebouria and Resnova (Asparagaceae, subfamily Scilloidea). Full text in Research Archive
• Løken, Solveig Bua (2025). More data, more resolution? Inferring phylogenetic relationships in selected genera of Scilloideae (Asparagaceae). Universitetet i Oslo. Full text in Research Archive Show summary

  The Scilloideae is a subfamily of bulbous plants within the asparagus family, with greatest species diversity in southern Africa. Many species are difficult to classify because variation in visible traits does not always align with genetic differences. Reliable classification is essential for understanding and protecting biological diversity. This thesis explores the evolutionary relationships in four challenging genera of Scilloideae: Dipcadi, Drimiopsis, Ledebouria and Resnova. Using data from both traditional and contemporary DNA sequencing methods, genetic relationships in the four genera are reconstructed. Additionally, it explores whether visible traits commonly used in classification are reliable for distinguishing species. The findings reveal that some species are well-defined, while others should be classified differently. We also find undescribed diversity and present one new species to science: Drimiopsis nana. Even based on advanced molecular methods, delimitation of these plants remains difficult, possibly due to rapid evolution and hybridization. This work highlights the importance of combining information from multiple sources to classify species well. By evaluating and comparing different molecular methods for understanding evolutionary relationships, this thesis also demonstrates the importance of using methods that are scientifically robust but at the same time accessible to a broad research community.

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