The leaves of desert plants that stores water and foodstuffs may either be cylindrical, as in the genus of stonecrops known as Sedum, or else have a prismatic shape as in the ice plant (Carpobrotus). Due to their water- storing properties, these plants that live in arid regions have a very fresh appearance. Water is stored inside the stems or leaves in broad, thin-walled cells. These leaves’ thick upper layer prevents water loss.
Another feature of desert plants’ flawless Creation is their spherical shapes. Because since it possesses the smallest surface area, the sphere is the most efficient volume for storing water. Desert plants’ thick stems, spherical shapes and pores that are closed during the day and open at night comprise a structure that reduces water loss due to evaporation.
Many plants store water in different places. For example, the Century plant stores it in its thick, fleshy leaves; the Cereus plant that opens at night in its underground bulb; and the cacti in their rounded stems. Plants such as the agave hold their grooved leaves open so as to catch the very infrequent rains that fall. In contrast, the leaves of plants such as Sarracenia minor that live in rainy areas, are like umbrellas, protecting the plants from excessive rain. Every plant has features appropriate to the conditions it lives in—a sign of Allah’s flawless creation.
Cacti’s prickly pears’ surfaces are flat. On their surfaces, nearly all have ridges or rows with a large number of thorny spikes. These plants are able to expand and contract according to the level of water stored in their inner tissues.
Everyone must have seen a cactus. However, most cacti have thorns or spines protecting its water-filled stem from animals. Its waxy upper layer protects the plant by insulating the effect of sun on it and reducing evaporation. The shiny wax reflects the majority of the light that falls on them; some are covered with white hairs to reflect more solar rays. In addition to their beauty, the features of cacti are also great miracles created to serve a variety of ends.
There is a plan, order and purpose in every component of a cactus, from its thorns to the white hairs covering it—all important evidence that cacti cannot have come into being by chance, but were created by a superior Intelligence.
Some species of cacti, especially the Window Leaves plant, bury their entire bodies just beneath the ground, protruding only the tips of their leaves above the surface. The tips of the leaves are transparent, yet further down, the leaves contain green cells with chlorophyll. These cells, arranged in the form of long lines, capture the light entering from the leaf tips to perform the process of photosynthesis. As a result of their very special structure, the plant reduces water loss to a considerable extent and hides from the blazing sun by remaining largely underground. It has no difficulty surviving in an environment that many living things could not endure for any length of time.
In addition to their many other attributes, desert plants have been created to be exceedingly resistant to drought conditions. For example, the American pygmy-cedar tree Peucephyllum and the plant Capparis spinosa, which can absorb a little moisture at night and remain green under even the most arid conditions, are completely resistant to drought. Many bushes and trees can also withstand drought, because their resistant leaves possess a number of features. Some like the Paloverde, for example, have very small leaves. Other leaves are needle- or bouquet-shaped; thanks to their small size, a reduced surface area is exposed to the drying rays of the Sun.
The leaves of some short-lived plants have pores on only one side, usually their top. This structure prevents water loss through evaporation, particularly under conditions of intense wind. Other leaves have pores on both surfaces, which absorb moisture from the air, especially during foggy conditions.
In some plants, especially Manzanita, the leaves are supported in such a way as to remain perpendicular. The surface areas are thus less exposed to the Sun, and water loss is reduced. Paloverde, which has only vestigial leaves that appear briefly in spring, performs its photosynthesis in the smooth, bright-green branches and twigs. That is because the possession of too many leaves in a desert environment means more water evaporating.
As you have seen, plants that resist the desert climate possess a number of different precautionary measures against the heat. It is clear that plants cannot take these precautionary measures separately from one another, since plants lack the necessary consciousness, reason and information. It is Allah Who creates every plant with the most appropriate and matchless features for the environment in which it exists.