Peculiarity of Anatomical and Morphological Structure of the Homosporous Fern Woodsia glabella r. Br. (Woodsiaceae) Associated with Its Petrophytic Lifestyle

This article considers the issue of specialization of rock ferns to environmental factors at the morphological and anatomical level to analyze the anatomical and morphological structures of the homosporous fern Woodsia glabella to identify its correlation with the petrophytic lifestyle in high latitudes. W. glabella is a Holarctic species, samples of which have been collected in the Komi Republic in the Yugyd Va National Park in crevices of rocks with moss cover. This obligate lithophyte (hazmophyte) has specific structural features at different levels of organization corresponding to extreme living conditions on damp rocks. At the organismal and organ levels, this is represented by the nanism of sporophytes, which allows the rosette short–rhizomatous biomorph to occupy a warmer ground-level ecological niche; bunch (cespitous) biomorph, long-lasting frond petioles, protecting the buds and fiddleheads from the drying effects of cold winds, high temperatures, excessive insolation, and transpiration; a bunch is also involved in the accumulation of its own humus, providing geophitization, in which bryophily plays an important role; frond pinnation, which increases the overall photosynthetic surface in vegetation conditions during a short summer; a summer green phenorhythmotype adequate to the climate; and a tendency to defoliation and the ability to switch to sporulation in the early phases of ontogenesis with time-different sporangia maturing. At the cellular and tissue level, these are thin pinna plates; large, chloroplast-containing epidermal cells with sinuous anticlinal walls; hypostomaticity; homogeneous loose mesophyll; low values of the dry weight of the blades; a small number of relatively large stomata per unit area; and the presence of phlobaphenes in the frond petioles that increase the resistance of the fern to changing environmental conditions. This study can shed light on the solution of many issues facing modern botany: the problems of structural evolution of plants, which are based on the processes of differentiation and specialization, as well as the diagnostics of species, adaptiogenesis, the doctrine of life forms, etc.