Parallelism in the Development of Life Forms of Species of the Genus Kudrjaschevia (Lamiaceae): Ontogenesis and Architectural Analysis

This study is aimed at studying the herb life forms of closely related narrowly localized endemic species of the genus Kudrjaschevia in Central Asia. A detailed description of life forms will make it possible to identify the morphological rearrangements of plants associated with the adaptation of species to certain ecological conditions. Our results will expand our understanding of the main directions in the evolution of morphs, which has practically not been studied in plants of the Central Asian flora. In the process of somatic evolution, individuals of this group have adapted to various specific habitats: rocks (K. nadinae, K. grubovii, and K. pojarkoviae), mountain screes (K. allotricha), and rocky outcrops of mountain slopes (K. korshinskyi). Using an architectural approach to describing plants, we show that various ecotopic and ecological–coenotic conditions do not affect the nature of the development of life forms of related taxa. Parallelism in the development of life forms in the studied species is manifested in the passage of the same phases of morphogenesis (primary shoot, main axis, and primary bush (clone)) and in the preservation of a monocentic biomorph. In the ontogeny in individuals of closely related species, a similar reiteration of axes is formed. Each axis is characterized as annually dying branching/nonbranching with radial symmetry, having opposite phyllotaxis, the apical meristem of which is realized in inflorescence. The long-term basis of plants in all representatives of Kudrjaschevia is built as a result of the sympodial sequential articulation of the short basal parts of the axes (residues) according to the monochasial/dichasial types. Despite the difference in the aerial parts of the studied rock (K. nadinae, K. grubovii, and K. pojarkoviae) and mountain-slope species (K. allotricha and K. korshinskyi), the shoot formation and the common long-term basis of the individuals are the same. The diversity of the aerial parts of the axes reflects the adaptation of plants to specific ecological conditions, while maintaining a genetically fixed, general development program.