Different plants have different ways to adapt to the desert. They have their own way to preserve and get water. Some plants have developed tap roots. These tap roots can extend to thirty meters below the surface to draw water out of the water table. Other plants have shallow roots to catch water as soon as it lands. Desert sand is well drained and water doesn’t sit around on top. This means water can soak into the ground very fast.
Some plants such as the spines or fur trees reduce the heat by facing leaves directly up or down to minimize surface area hit by the sun so less water is evaporated.
Africa's baobob tree(Adansonia digitata) has a thick, water-storing trunk, to help the plant to store sufficent water for survival, stubby branches and large, white flowers. It can live more than 1,000 years living in the desert.
Other plants like the Joshua tree have small knife like leaves that have a very small surface area. The small surface area means that less water is evaporated. This tree also has a waxy resin that prevents much water from evaporating.
Another plant called stone plants(Mesembryanthemums) exposes only a few of its leaves. Most of them are underground along with the main body. This is done so it doesn’t loose all its precious water to the sun. The tree is also kept cooler. They have transparent leaf tops to allow sunlight to enter the plant to help to increase the rate of photosynthesis.
The Mosquite tree has adapted to the desert by having roots that can extend 30m into the ground. This is so it can tap into the underground water supply.
The cactus has spine/needle like leaves which reduces the surface of the leaves to decrease the loss of water in the plant through transpiration, especially in the extremely hot weather.
Reference:
http://scienceray.com/biology/ecology/plants-and-animals-adaptations-to-the-desert-biome/
Book: Plants
