I’m writing this from my new suite, on a couch that belongs to us, in a kitchen that we get to use at any time of the day, filled with appliances we bought ourselves and food we share and pass around. The leaf and stem structure of succulents is also characteristic of many solonchak plants, although the latter have no adaptations for lowering transpiration.So suddenly it’s September. Some, for example, opuntias, are used as animal feed. Succulents are widely used as ornamentals (cacti, aloe) and textile plants (agave). The formation of endogenous water during respiration maintains hydration of the cell contents and, thus, is of great importance in the life of succulents. Part of the CO 2 is released upon decomposition of the organic acids under the action of light. During dry seasons the stomata are closed, and the CO 2 serves as the source of carbon. In darkness the leaves store substantial quantities of CO 2, which results in formation of organic acids. Succulents grow slowly as a result of their economical expenditure of water and the nature of their carbon metabolism. At the same time, however, the protoplasm is characterized by low elasticity, and, therefore, the plants cannot tolerate dehydration. Growing under conditions of intense heat, they have developed an increased resistance to high temperatures as a result of the great viscosity of the plasma and the high content of bound water. The ability of succulents to expend small amounts of moisture is made possible by the heavy cutinization of the epidermis, by the presence of hairs, by the low osmotic pressure of the cellular juice, and by the presence of only a small number of low-lying stomata. The stems of some species of cacti store 1,000 to 3,000 kg of water the plants often serve as a source of water for humans and animals during drought.
The leaves and stems have highly developed water-bearing parenchyma. The distinctive physical appearance of succulents, which evolved in the process of historical development, is related to their ability to accumulate water in their leaves or stems and to expend the water sparingly during prolonged drought. The few succulents that occur in the USSR belong to the family Crassulaceae. Succulents grow in the deserts of Central, North, and South America some are also encountered in the deserts of southern Africa. A perennial plant with juicy, fleshy leaves (agave, aloe) or stems (cacti, certain spurges) a special type of xero-phyte.
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