Vol 109, No 10 (2024)

The genesis of the syncarpous gynoecium (lysicarpous variation) and ovule in Lysimachia vulgaris is studied. The ovary is superior. The gynoecium is formed by 5 carpels, as evidenced by the presence of the remains of 5 septae between fused adjacent carpels on the wall of the ovary. It is characterized by a zonal structure, with the synascidiate zone being the most extensive. The distal part of the gynoecium is occupied by the asymplicate zone. The ovary region, which includes an upper narrow rounded sterile part of the placental column, can be considered as the symplicate zone. At the base of the gynoecium, a short gynophore is formed, which projects into the center of the basal part of the gynoecium. In the lower part, it does not fuse with the placental column, but in the middle and upper parts gynophore transforms into a columella with central-angular placentae around it. Ovules are formed on intrusive placentas and arranged in offset rows. In the eustele of the pedicel, a ring of 15 collateral vascular bundles appears, which enter the elements of the calyx, corolla, and androecium. In the central part, a plexus is arranged to innervate the gynoecium, with 5 bundles extending in the remnants of the gynoecium septae to the upper part of the style. In the very center, 7–10 bundles innervate the gynophore, extend into the placental column, and their branches extend into the placenta and ovules. The fruits are septal-loculicidal capsules. The dehiscence occurs through longitudinal fissures in the area of septal (almost reaching the base) and locular (only at the top) grooves.

The ovule is hemi-campylotropous, medionucellate, bitegmal, mesochalazal, sessile, with a hypostase and an integumentary tapetum. The mature seed is acuminate and curved at the micropylar and chalazal ends. A cellular endosperm and a straight dicotyledonous embryo are formed in it. The seed coat is formed by both integuments. During development, the endotesta, exotegmen and mesotegmen are destroyed. The exotesta, made up of elongated thick-walled cells, and the endotegmen, formed by thin-walled cells, are preserved. Tannins accumulate in the cells of both layers.

A conspectus of the genus Dasiphora Raf. (Rosaceae) species in the flora of the Russian Far East is given, comprising accepted five species: D. fruticosa (L.) Rydb., D. davurica (Nestl.) Kom., D. mandshurica (Maxim.) Juz., D. flava (Vorosch.) Gorovoj, Pshenn. et S. Volkova, and D. gorovoii Pshenn. These species differ in the morphology of the leaf blade and indumentum of the stipules, peduncles, and calyces. An updated key for the species identification is provided. A drawing from the J. Amman’s work (1739) is designated as the lectotype of D. davurica .

The research of gynodioecy of Thymus pannonicus All. was conducted in 5 populations (CPs) in steppe and meadow-steppe communities of the Altai Territory. Statistically significant differences between bisexual and pistillate flowers in the length of lower stamens or staminodes and their anthers ( p < 0.05) were revealed in the population CP1. The range of staminode length in pistillate flowers is 0.1–1.2 mm; the range of stamen length in bisexual flowers is 1.5–2.0 mm; the range of anthers length was 0.00–0.35 mm and 0.39–0.41 mm, respectively, for pistillate and bisexual flowers. 11% of females in the sample develop exclusively flowers with small (0.1–0.3 mm long) staminodes without anthers. A high coefficient of variation of staminode parameters in the females was detected: 44.2 and 42.7% (for staminodes and anthers, respectively), and a low coefficient of variation of stamen parameters in hermaphrodites: 7.8 and 3.1% (for stamens and anthers, respectively). A high frequency of androecium developmental disorders may indicate the instability of the genome of T. pannonicus . The females were found to make a prevailing majority in all 5 studied coenopopulations of the Altai Territory: 69–90% of all generative individuals. In general, T. pannonicus is characterized by a high frequency of females in steppe and forest-steppe habitats in both the European and Asian parts of the species range: 38–90%.

The comparison of the structure of shoot systems of forest-forming species of temperate zone trees with architectural models, including those which the authors of the concept of architectural models and other researchers indicate for the temperate climate trees (namely, Rauh , Scarrone , Troll , Noseran , Attims , Koriba , and Leewenberg ), has shown that none of the models is in complete compliance. This is due to the fact that the sets of characters used for describing the models and observed in the studied species do not coincide, and the features characterizing the models need to be either supplemented or clarified with regard to seasonal climate conditions, or are to be replaced with more clearly formulated ones, or are not suitable at all. Six new constructive combinations of characters were proposed for the studied species. The issue of architectural models of the studied species can be finally resolved after studying the structure of shoot systems in other tree species as well as shrubs and woody temperate vines. This will make it possible to identify both new variants of characters and their new combinations, as well as to confirm the validity of the already proposed six combinations.

A rare chrysophyte species, Uroglena kukkii , was recorded in the waterbodies of the mountain forest zone of the South Urals. Described from Estonia, this species was first recorded in Russia in St. Petersburg. The second Russian discovery of the species U. kukkii indicates a wider distribution of the species. The morphology of the colonies and stomatocysts of U. kukkii was studied using light and electron microscopy. This paper compares the morphological characteristics of U. kukkii stomatocysts from the two habitats in Russia with samples from the type locality, and specifies the conditions for the mass formation of the stomatocysts.

International Bryological Conference and field school for young scientists “ Bryophytes: systematics, distribution, ecology, protection ” , dedicated to the 300th anniversary of the Russian Academy of Sciences took place on August 23–29, 2024 in Apatity of Murmansk Region at Kola Science Center of the Russian Academy of Sciences. Fifty bryologists, including students, graduate and post graduate students from 13 cities of Russia and 2 countries abroad participated in the conference. In total , nine plenary presentations were submitted and discussed, as well as 23 presentations within the framework of 3 sections: “ Phylogeny and systematics of mosses and liverworts ” , “ Ecology and phytocenology ” , “ Flora and biogeography ” , and six posters.