Vol 110, No 4 (2025)

To search for new biomorphological characters significant for taxonomy, the morphogenesis of Phlomoides agraria, P. tuberosa, P. tuvinica (subsect. Phlomoides), and P. alpina, P. oreophila, P. pratensis (subsect. Alpinae) was analyzed, as well as herbarium specimens of other species of the genus Phlomoides from different subsections. Manifestations of recapitulation by phyllotaxis in some representatives of the genus were considered and analyzed, and one of possible directions of somatic evolution within the genus was determined on this basis.

During a comparative analysis of the morphogenesis of the above-mentioned species, biomorphological differences were revealed between closely related species: P. agraria, P. tuberosa (subsect. Phlomoides) and P. alpina, P. oreophila (subsect. Alpinae). We have established that these species, confined to certain vegetation zones, are characterized by the constancy of their life form. As an additional diagnostic feature, the structure of the underground part of the plants is proposed to use: P. agraria forms a long rhizome, P. tuberosa – a short one; P. oreophila – a caudex, and P. alpina – a short rhizome.

A relationship was established between the shoot formation model, the peculiarities of the location of generative shoots on skeletal shoots and the belonging of the species to one of the clades identified in the course of molecular genetic studies, which indicates the prospects for using these characteristics in the taxonomy of the genus Phlomoides.

Recapitulation by alternate phyllotaxis is described at the beginning of ontogenesis in P. agraria and P. tuberosa, both following the sympodial model of shoot formation. In monopodially growing plants of P. alpina, P. oreophila and P. pratensis, it is completely absent. It was found that P. tuvinica plants, which follow the monopodial model of shoot formation, retain alternate phyllotaxis on skeletal rosette shoots and opposite decussate phyllotaxis on axillary generative shoots throughout their ontogenesis. The presence of two phyllotaxis variants in P. tuvinica individuals suggests that this species is closest to the ancestral type, i. e. a non-durable semi-rosette monocarpic plant. It is assumed that somatic evolution proceeded from a non-durable monocarpic plant with a semi-rosette shoot to a perennial polycarpic plant through both monopodial and sympodial growth patterns of shoot structures. With monopodial growth of a plant, the shoot structure changes from the original semi-rosette to rosette, while in the case of sympodial growth of a plant, the semi-rosette structure of the shoot is retained.

In September 2024, samples with Vaucheria were collected in the Northern Dvina River mouth at the cities of Arkhangelsk and Severodvinsk (Northern European Russia). Five species were identified, including V. synandra, which is a new record for Russia. Vaucheria birostris and V. medusa are newly recorded for the Arkhangelsk Region. The morphology of these species is documented by microphotographs. New localities were established for V. intermedia and V. macounii.

In the massif of native old-growth spruce forests located at the junction of the Verkhnetoyemsky and Ustyansky districts of the Arkhangelsk Region, the species of plants, fungi and lichens listed in the Red Data Books of Russia (Calypso bulbosa, Lobaria pulmonaria and Sarcosoma globosum) or Arkhangelsk Region (Acolium karelicum, Arthonia vinosa, Chaenotheca gracillima, Corydalis solida, Poa remota, Pycnoporellus alboluteus, Ramalina thrausta) were found. The surveyed massif can be classified as a biologically valuable forest by both the structure of the tree stand and the presence and number of specialized and indicator species. Nowadays, native old-growth forests, both in the North-West of Russia and in Europe as a whole, are rare plant communities. Their preservation is important not only for the survival of species listed in the Red Books, but also for the preservation of the general biodiversity associated with the old-growth forests and ensuring the sustainability and restoration of natural forest communities. The creation of a specially protected natural area within the boundaries of the studied forest massif is recommended.

The Arctic region requires a high-quality knowledge of its nature. “Tundra Studies. Terrestrial Ecosystems of the Arctic” by O.I. Sumina, released in 2024, is the first and so far the only textbook on this extremely important subject. It considers specific properties of Arctic terrestrial ecosystems, discusses historical processes of their formation and transformation under human influence. The textbook can be useful in the educational process in the fields of ecology, geography, geobotany, nature and resource management.