The data on the biomorphological and spatial structure of a previously unstudied population of Amelanchier ovalis growing on the north-eastern slope of Mount Sagitma of the Kumtorkalinsky Range in the Republic of Dagestan are obtained. A. ovalis is a relic listed in the Red Book of the Republic of Dagestan as endangered – 1 (CR). The floristic composition of the community with the participation of A. ovalis is described, an attempt is made to propagate it by green and lignified cuttings and seed material of plants of the rare species in order to create a resource introduction planting and further reintroduction into natural communities to increase the population of this species. As a result of the conducted geobotanical studies, an association of Сarpineto-pineto-quercetum rara-herbosum with the participation of A ovalis was identified. In the sparse herbage, 34 species of higher vascular plants are noted, the full floristic composition of the community is represented by 62 species. There is no pronounced dominant in the grass-shrub layer, forest species are rarely represented. The soils are poorly developed psammozems with sandstone blocks (15–40%) exposed on the surface, covered with epilithic lichens. The accumulation of moisture from autumn-winter rains in deeper soil horizons allows the A. ovalis population to exist here for a long time (70 years or more).

The paper presents the results of the study of variability of fruit and stone morphological traits of natural apricot (Prunus armeniaca L.) populations along the altitudinal gradient. Three model cenopopulations of Inner-mountain Dagestan along the Avarskoe Koysu river basin, which differ most strongly along the altitudinal gradient (600–1420 m a.s.l.), were chosen as reference points. Comparative analysis of P. armeniaca cenopopopulations in Dagestan conditions showed that wild apricot in general is characterised by small fruit and stone sizes, the average geometric diameter of fruit and stone was 25.4 mm and 14.0 mm, respectively, and the weight averaged 10.6 g and 1,3 g, with the highest values for most traits at 1050 m altitude and the lowest at 1420 m altitude. Analysis of variability (CV, %) of quantitative traits showed that variability of traits decreases along the altitudinal gradient, which may indicate the formation of adaptive shape and size of fruit and stone with increasing altitude. The results of the study were confirmed by the results of onefactor variance, regression and discriminant analyses. The highest dependence on the altitude factor in terms of variance components was found for the following traits: stone width (η² =32,5%), fruit reproductive effort (31,7%) and average stone diameter (30,4%). Regression analysis revealed that the altitude level negatively affects the fruit size of natural P. armeniaca cenopopulations, leading to a gradual decrease in fruit width and thickness, which eventually leads to the formation of oval fruits. Correlation coefficients showed a noticeable significant negative relationship of mean fruit diameter (r_xy= -0,36) and fruit weight (r_xy= -0,34) with altitude. Meanwhile, stone and seed thickness related dimensions conversely increased with altitude, ultimately leading to an increase in fruit reproductive effort (r_xy=0,55). The results of the discriminant analysis clearly showed that along the first axis, differences between CPs in fruit size along the altitudinal gradient were reflected, and along the second axis, the change in apricot optimum to the peripheries was reflected, which is consistent with the assessment of the vitality of the cenopopopulations. The index of vitality of cenopopulations (IVC) showed that the maximum productivity of cenopopulations occurs at altitudes of 800–1200 m, with a low value of dimensional plasticity (ISP=1,12) indicating relative stability of fruit, stone and seed sizes along the altitudinal gradient. 

The article presents the justification for the allocation of a new protected area from the point of view of preserving the biological diversity of flora and vegetation. The territory of the proposed natural monument «Buzhora Forest» is the western outpost of the oak forest in the NorthWestern region of the Caucasus. The flora of this area includes 166 different plant species from 58 families and has special characteristics related to the presence of species from the North-Western Transcaucasian and Kuban broad-leaved areas. An important feature of this forest area is the presence of two populations of a rare species of snowdrop, which is listed in the Red Book of the Russian Federation – the folded snowdrop (Galanthus plicatus M. Bieb.). The second important feature of the vegetation cover of the Buzhora Forest natural monument is the growth of oak and oakhornbeam forests on the border of its area. They are located on the border with the CrimeanNovorossiysk province and represent a heterogeneous environment with cloverleaf pinnate and hornbeam in the undergrowth and in the second tier. The diversity of cenotic spectrum is marked: oak-hornbeam, oak-hornbeam-hornbeam-hornbeam, oak-jasneberry-hornbeam and hornbeam communities prevail. A typical forest community is oak-hornbeam-hornbeam forest with clematis. Of considerable interest are the shibliak communities, which are located on the border of the nature monument and include Mediterranean plant species. Rare and endangered plant species were also found here, including Steveniella satyrioides, Orchis wulffiana. Finding of the latter species of orchid in Bujorsky forest is the second registration of this species in the territory of North-Western Transcaucasia. Forest oak and oak-hornbeam communities on the southern slope of the watershed are important habitats for various rare and protected animal species, including Bolivaria brachyptera (Pallas, 1773), Saga pedo (Pallas, 1771) and others. The northwestern portion of the natural monument includes a patch of forest that is home to the Mediterranean tortoise. 

A new population of the red-listed species Acantholimon schemachense (Plumbaginaceae) on the territory of Magaramkentskiy district in Dagestan was studied. Phytocenotic habitat of individuals and biometric indices were determined, geobotanical description of the community was carried out. It was noted that the majority of bushes with sizes from 10x10 cm² to 15x25 and 20x35 cm² were in a mature generative state. At the same time, large shrubs with sizes of 70x50 cm², 40x50 cm² were in senile and sub-senile state. Based on geobotanical studies, the association Acantholimonetum artemisoso-graminosum was identified. 

A new form Dentaria quinquefolia f. pallidiflora Melamud is described from the North Caucasus. The new form differs from the type form in the white (when dry, pale pink) color of the petals. (In Dentaria quinquefolia f. quinquefolia the petals are violet or bright pink). The type material was collected in the spring of 2024 in the Mezmay Gorge (basin of the Kurdzhips River within the Lagonaki Highlands). A detailed description of the locus classicus is given, and information about finds of this form in other regions is provided. Analysis of the locations of the described form allows us to consider it a subendemic of the North Caucasus, sometimes irradiating into the adjacent regions of Ciscaucasia and Transcaucasia. Recommendations for herbarization of representatives of this species are given. 

In practice, it is difficult to distinguish closely related species from each other, which is usually associated with high intraspecific polymorphism. The aim of this work is to assess the variability of the species R. oxyodon, R. prokhanovii and R. sosnovskyana. At the first stage, 42 morphological characters were analyzed. The same samples were studied in relation to the polymorphism of ISSR markers and the variability of the chloroplast spacer trnL-trnF. Analysis of the morphological characters of R. oxyodon, R. prokhanovii and R. sosnovskyana by the principal coordinates method showed the impossibility of their strict differentiation as independent and equivalent species. The same result was obtained when analyzing the polymorphism of 115 ISSR markers. Data on the variability of the chloroplast spacer trnL-trnF of the above-mentioned species also showed that the existing polymorphism is not associated with division into three species. 

The paper presents data on 36 species of corticolous lichens of the Chechen Republic (city district Grozny, Nozhai-Yurtovsky, Shartoysky districts). For the first time in the republic, 17 species and 6 genera of lichens were recorded. The rare for the Caucasus and news for Chechen Republic, rarely collected species are provided. These include: Bacidia polychroa, Biatoridium monasteriense, Physciella chloanta, Ramalina asahinana, Ropalospora viridis, Stictis radiata, Usnea wasmuthii. 

Five species of lichens have been propose for inclusion in the list of protected species in Krasnodar Territory – Bactrospora patellarioides, Lecanographa lyncea, Leptogium hibernicum, Scytinium subaridum, Usnea cornuta. For each of them, the characteristics of distribution, ecology, population estimates, limiting factors and protection measures are given. The categories of status and categories of extinction threat of the taxon according to IUCN criteria are proposed. For the species Leptogium asiaticum, it is necessary to increase the category to 1 CR due to habitat destruction in the lower reaches of the Achipse River. For three species (Candelariella viae-lacteae, Opegrapha celtidicola, Thelopsis isiaca) from the list of taxa requiring special attention to their condition in the natural environment of Krasnodar Territory, it is propose to change the category and include them to the list of protected species due to decline in numbers and deterioration of populations over the past 10 years. 

The issues of territorial distribution of the rare flora of the Eastern Caucasus Paeonia mlokosewitschii Lomak are considered. The current state of the population on the left bank of the Samur River within the Rutulsky district is shown. A preliminary clarification of the boundaries of the species' range in this area has been carried out. A fairly highly vital population grouping of Paeonia mlokosewitschii has been identified in the Rutulsky district in the vicinity of the village of Khiyakh, and in other places (near the villages of Korsh and Tsakhur) the groups are small in number. The phytocenotic association of the species is diverse: from dry slopes with shrubby thickets of the shiblyak type, to forest communities (aspen stake), where the largest number of individuals is noted. Recommendations for monitoring the assessment of the spatial distribution of this species and measures for its protection are proposed.