Скульптурные элементы из кремнезема различаются по форме, размерам и расположению на ребрах и в бороздках междоузлий стебля и веточек: тонкие продольные, иногда анастомозирующие тяжи, цилиндрические с округлой верхушкой или конические мамиллы, бугорки и шипики. Продольные тяжи, крупные бугорки и шипики располагаются на ребрах, мамиллы и тяжи из слившихся мамилл-в основном в бороздках. Ультраскульптуру поверхности составляют полусферические, шаровидные или слегка вытянутые бородавочки, покрывающие поверхность бороздок, мамиллы и особенно побочные клетки устьиц; у Equisetum palustre имеются специфические булавовидные стерженьки, располагающиеся правильными рядами по краям побочных клеток, обращенным к устьичной щели. Для всех видов и гибридов приведены подробные описания скульптуры из кремнезема, формы, расположения и орнаментации устьиц. Такие признаки как наличие, форма и расположение скульптурных элементов, расположение устьиц, форма и орнаментация побочных клеток могут быть использованы в систематике и филогенетике хвощей. Споры видов Equisetum сферические, не обладают специфической орнаментацией, их признаки не могут использоваться в систематике.

Each species besides of having the unique morphological pattern also has an unique ecologo-climatic niche and geographical range. The study of ecologico-climatic and geographic divergence can make significant contribution to understanding of the species genesis and its volume. The purpose of this paper was to compare the ecologo-climatic niches of the closely related species Stipa sareptana and S. krylovii in order to reveal their identity. The research allowed specifying the areas of both species. Using GIS methods and based on the points of presence and six independent bioclimatic characters, their potential ranges -areas where the climatic conditions are favorable for growth -were identified and ecologo-climatic niches revealed.It was established that the most important factors determining the distribution of S. krylovii and S. sareptana are the mean annual temperature and seasonality of precipitation. Other factors play a subordinate role. The comparison of ecological niches, generated by MaxEnt, showed their differences at a statistically significant level. Каждый вид, помимо уникального морфотипа имеет уникальную эколого-климатическую нишу и географический ареал. Изучение эколого-климатической и географической дивергенции может внести значительный вклад в понимание генезиса вида и его объема. Целью данной работы было сравнение эколого-климатических ниш близких видов Stipa sareptana и S. krylovii с целью выявления их идентичности. Исследования позволили уточнить ареалы обоих видов. На основе координат местонахождений и 6 независимых биоклиматических переменных были определены их потенциальные ареалы -районы, где климатические условия благоприятны для роста, и выявлены эколого-климатические ниши. Установлено, что наиболее важными факторами, определяющими распределение S. krylovii и S. sareptana, являются среднегодовая температура и сезонность осадков. Другие факторы играют второстепенную роль. Сравнение экологических ниш, созданных программой MaxEnt, показало их различия на статистически значимом уровне.Ключевые слова: эколого-климатическое моделирование; MаxЕnt; Stipa krylovii; S. Sareptana; распространение Введение Род Stipa L. принадлежит к трибе ковылёвых (Stipeae Dumort.) семейства злаки (Poaceae Barnh.) и является одним из наиболее крупных родов (Цвелев, 1976;GPWG, 2001). Род насчитывает около 150 видов, распространенных в умеренно теплых (за исключением значительной части лесной зоны) и субтропических странах Евразии, а отчасти так

Matteuccia struthiopteris (L.) Tod. – Ostrich fern (Onocleaceae) is the circumboreal species widely distributed in the temperate zone of the northern hemisphere. In the paper, we presented the results of the observations on the developing population of M. struthiopteris on the man-made lawn situated in the University Grove of Tomsk State University (Tomsk, Russian Federation). In the original making of the lawn, the ground was replaced by new rich soil, which was taken in early summer of 2007 from a native site situated 6.65 km towards south-west from Tomsk University. The formation of the plant community on the new lawn occurred mostly naturally, and sporophytes of this fern appeared naturally. The first sporophytes on the new lawn were detected in 2009, occurring initially in the significant numbers, recorded here. During the time of observation (2009–2018) the number of sporophytes decreased from an original 263 to 96, i.e. 63.5% of sporophytes died. The initial population in 2009 included only juvenile sporophytes. No spore-bearing sporophytes appear during the period of observation. For detection of the source of spores, from which the population on the lawn was formed, we selected three populations having fertile sporophytes, and conducted a molecular-genetic analysis. Two of the analyzed source populations were found to be situated at 160–365 m distance from the developing population and one population occurs near the place where the soil for new lawn making was taken. We used the ISSR method for analyzing the genetic diversity of populations and processed the results by software STRUCTURE Version 2.3.4. The result show, that new population, and population from the soil taking point belong to the same group. The coefficient of Nei’s genetic identity between these populations is high (I = 0.931). This confirms the origin of the new population from spores contained in the soil used for the lawn construction.

Horsetails are a complex taxonomic and systematic group. Therefore, the study of the geographical distribution of these species is necessary for a better understanding of the phylogeny of this family. We concluded an analysis of the distribution of 5 species of horsetail of the subgenus Equisetum (Equisetum, Equisetaceae): E. arvense L., E. fluviatile L., E. palustre L., E. pratense Ehrh., E. sylvaticum L. using the maximum entropy method implemented in the MaxEnt program. Modeling was carried out using climate variables from the WorldClim global climate base. Simulation results show good simulation quality. In 3 out of 5 species, the AUC of the test sample was in the range of 0.9–1, and in 2 species — 0.8–0.9. In general, for most species, a plausible picture of their intended distribution has developed. The obtained models suggest that the territory of Russia is favorable enough for the growth of horsetails. Analysis of the contribution of 14 bioclimatic variables to the distribution of the studied species revealed that the most important variables are: annual mean temperature, isotermality, temperature seasonality, max temperature of warmest month, temperature annual range, mean temperature of warmest quarter, mean temperature of driest quarter, mean temperature of coldest quarter, annual precipitation, precipitation of wettest month, precipitation seasonality, precipitation of driest quarter, precipitation of warmest quarter, and precipitation of coldest quarter.

Matteuccia struthiopteris (L.) Tod. – Ostrich fern (Onocleaceae) is the circumboreal species widely distributed in the temperate zone of the northern hemisphere. In the paper, we presented the results of the observations on the developing population of M. struthiopteris on the man-made lawn situated in the University Grove of Tomsk State University (Tomsk, Russian Federation). In the original making of the lawn, the ground was replaced by new rich soil, which was taken in early summer of 2007 from a native site situated 6.65 km towards south-west from Tomsk University. The formation of the plant community on the new lawn occurred mostly naturally, and sporophytes of this fern appeared naturally. The first sporophytes on the new lawn were detected in 2009, occurring initially in the significant numbers, recorded here. During the time of observation (2009–2018) the number of sporophytes decreased from an original 263 to 96, i.e. 63.5% of sporophytes died. The initial population in 2009 included only juvenile sporophytes. No spore-bearing sporophytes appear during the period of observation. For detection of the source of spores, from which the population on the lawn was formed, we selected three populations having fertile sporophytes, and conducted a molecular-genetic analysis. Two of the analyzed source populations were found to be situated at 160–365 m distance from the developing population and one population occurs near the place where the soil for new lawn making was taken. We used the ISSR method for analyzing the genetic diversity of populations and processed the results by software STRUCTURE Version 2.3.4. The result show, that new population, and population from the soil taking point belong to the same group. The coefficient of Nei’s genetic identity between these populations is high (I = 0.931). This confirms the origin of the new population from spores contained in the soil used for the lawn construction.