The desert is never completely empty and the rains, even very rare, maintain a varied vegetation. It is more abundant in the oases or the bed of the wadis (rivers), but isolated plants can be found in the middle of the dunes.
Plants have developed many techniques of adaptation to the desert. Their roots, very long, capture the slightest trace of water on the surface or at great depths. Fatty plants, such as yucca, store rainwater in their spongy tissues, their spines limiting water evaporation.
Shrubs (hibiscus, acacia…) grow at a distance from each other so as not to compete with each other. Seeds buried in the ground sometimes wait for rain for years. We then see appearing in the desert lilies, dandelions and other lupines.
How do plants survive in the Sahara desert?
In the desert there are plants that only grow during the wet season and then they die. But their seeds know how to stay alive during the dry months and germinate when the water comes back. These plants are called annuals because they do not live all year round, but they reappear every year.
There are also many perennial plants in deserts. They live for several years, but sometimes become inactive and stop growing during the dry season.
Having thorns instead of leaves allows the plants to save water. Dry thorns do not lose water evaporation when it is hot, leaves do. In addition, some cacti are covered with a dense network of thorns that protects them from the sun’s rays.
Another strategy to survive during drought is to have long roots to fetch water from far away! Some trees (Mesquites for example) have very long taproots that go down very low into the ground, up to more than 30 meters, to reach the water which is at great depths.
What is the name of plants that do not need very little water?
The Greek root of this word speaks for itself, since ‘xeros’ means ‘dry’. A xerophyte plant is therefore adapted to arid conditions and can live quite well in very dry environments where rain only falls very rarely, or not at all for several months.
For this, during its evolution, the plant has developed various ‘tricks’ to limit evapotranspiration and to absorb the little water available.
To limit evaporation, the leaves (if any) are often covered with clear bloom, curl up, are tough, covered with very fine scales, hairy, transformed into stings.
Some plants grow at ground level or take on a spherical shape to limit the drying effect of the wind, others have stems swollen with juices that can contain nearly 90% of their weight in water. Still others develop a very extensive root system at depth or on the surface in order to pump water from the water table or to capture the slightest dewdrop.
How do plant manage to stay hydrated?
To ensure that they will have enough water to live, some plants prevent other plants from growing near them.
Creosote Shrubs (Creosote Trees) make toxic chemical compounds that they release into the soil around them that prevent other plants from growing. This harmful influence is called allelopathy. In this way, each shrub eliminates competition for water and nutrients, and it will have everything it needs to live.
8 Plants that live in the Sahara Desert
1) Desert Coloquinte
The Asian coloquint makes smooth and almost spherical fruits that quickly change from dark green streaked with yellow to lemon yellow and then to white as they ripen. These fruits are very similar to the coloquintes of France.
In general, they are locally grouped and abundant and are very rarely found in isolated individuals. It is not advisable to eat them because they contain a rather powerful alkaloid in small quantities. Consumed in large quantities, it is used as an abortifacient by Moorish women. Animals are wary of it, camels do not touch it.
Its leaves are as big as cabbage leaves, they are stiff and persistent. It produces beautiful small blue flowers. Its sap, a white latex which runs as soon as one touches the plant, is corrosive and toxic. It is because of this sap that no herbivore dares to eat it.
It is dangerous for humans, even by contact. To touch the sap with your finger in your eyes can lead to serious eye problems and even blindness.
Its powerful active ingredients are used in the composition of many artisanal remedies.
Perennial plant, forming large bluish green touches. The stems are more or less woody. Capsules yellow domed, pale yellow, rather large. The plant has a pleasant smell. The small very divided leaves are covered with a silvery down.
Many medicinal properties: analgesic, antiseptic, anti-diarrheal. The small leaves, dried or not, are crushed with the fingers and swallowed with a glass of water. Helps in infusion to fall asleep. The taste is a little bitter.
4) Desert cabbage / desert salad
Sahara-arabic species common throughout the Sahara. Annual plant bluish-green with broad slightly fleshy euilles, purple flowers in clusters at the end of the stems.
This plant grows quickly after the rain and makes the desert look like a meadow. Excellent pasture for camels and goats. The leaves can be eaten cooked added to porridges or sauces.
Acacia provides, apart from the palm groves, the only shade allowing travelers to protect themselves a little from the sun.
It has very hard spines that can measure up to 8 cm. This does not protect it from camels or goats that even manage to climb the tree to enjoy it better.
6) Palm dates
It is the indispensable relay for the use of the scarce water resources of the oases. It is used for many purposes.
The trunk is used for heating and lumber, the fibers and leaves are used for basketry, the fruit core is used for cattle feed. In the absence of irrigation, palm trees have roots up to 20 times more developed than their trunk to fetch water from deep inside and reduce the areas exposed to transpiration. The planted date core gives a palm tree, but only the cuttings ensure good quality dates.
The pollination of female palms by male palms is done at home. The date is rich in sugar and is used as a staple food by nomads.
Large tree with rough bark with small scaly leaves, nested forming a sheath around the branches. Flowers grouped in slender kittens with 5 stamens on the young shoots. The wood is used for housing.
This tamarix is often planted to make palisades or windbreaks. The wood is little used to make fire because it smokes a lot. The seeds resembling chickpeas are collected from the ground by nomadic women and used to tan the skins.
8) Matricaria chamomilla
The matricaria chamomilla is an aromatic and vegetable plant.
It is used as a condiment impossible to circumvent in the culinary dishes and tisaines of the area of the south.
Gathered especially in the hamadas in spring.
Plants do not have an easy life in the desert! They have to be able to keep from drying out in spite of hot air and dry soil. Plants absorb water from the soil through their roots and lose water through transpiration and evaporation. But because water is not easy to find in the desert, many of the plants that live there have special adaptations to save water in many ways.
They can limit the amount of water they lose through transpiration and evaporation, or increase the amount they absorb, or build up water reserves.
Plants that are able to survive in very dry places are called xerophytes. It is a word created by two Greek words: xero (dry) and phyte (plant).
Plants, such as cacti, that store water to survive the dry season are called succulents. When it rains, even very little, they quickly absorb as much water as possible through their roots and store it in their stems, leaves, or roots.