Anatomical and morphological features of the vegetative organs of succulent plants regards growth conditions

摘要

Anatomical-morphological characteristics of leaves and stems of plants of succulent type Crassula perforata Thunbg., C. socialis Schonland (Crassulaceae), Senecio rowleyanus Jacods, and S. herreianus Moritz Kurt Din. (Asteraceae) from extreme habitats were studied. Basic quantitative parameters of anatomical indices were presented. The comparative analysis of the structure of vegetative organs of succulents was carried out. Several common features, which result from adaptation to such conditions of growth (characteristic peculiarities of the external structure, weak differentiation of mesophyll, considerable development of the water-bearing tissue) and features, which distinguish the studied species (the type of leaf mesophyll, presence of trichomes, type of the stomata apparatus, the degree of the conductive system development) were registered. The species which we studied is mainly spread in arid regions with warm climate and is capable of special САМ – type of photosynthesis, which enables it to survive under conditions of water deficiency and high temperature stress. In addition, arrangement of leaves in rosette makes it possible for the latter to shadow the other ones and condense moisture near the stem base. However, it can be seen from our research that under conditions of temperate climate plants, studied by us, preserved the anatomical structure, typical of tropical representatives from xeric habitats and have similar survival strategy, which is manifested at all levels of organisation: morphological, anatomical and physiological.