The Sahara is the largest desert in the world

The Sahara (Arabic: الصحراء الكبرى‎, aṣ-ṣaḥrā´ al-kubra, "The Greatest Desert " is the world's largest hot desert. At over 9,400,000 square kilometres (3,630,000 sq mi), it covers most of Northern Africa, making it almost as large as Europe or the United States. The Sahara Desert stretches from the Red Sea, including parts of the Mediterranean coasts, to the outskirts of the Atlantic Ocean. To the south, it is delimited by the Sahel: a belt of semi-arid tropical savanna that comprises the northern region of central and western Sub-Saharan Africa. The Sahara is one of the hottest places on Earth. Even though temperatures there may rise to 136 F (57.7 C), its dryness, not heat, that makes a place like the Sahara a desert. The frozen continent of Antarctica is so dry that some scientists consider it a desert, too.As the world's largest desert, the Sahara receives less than three inches (7.6 cm) of rain a year. Even in its wettest areas, rain may arrive twice in one week, then not return for years.There are many trees in the Sahara like Cactus.The stem of the Saguaro Cactus stores all of its water. The stem is green. Photosynthesis occurs in the top layer of the stem instead of in leaves. This plant has another adaptation that is hidden from us. This is its large net of roots -- that extend far away from its trunk. How would these roots help a desert plant? The roots collect water after rain. Stored in the pleated expandable stem, the water keeps the saguaro alive until the next rain. Saguaro fruit is used in jam and woody skeletons are used in building materials. The Saguaro only grows in the Sonoran Desert, which stretches through parts of Arizona, California, and Mexico.This cactus can grow as tall as fifty feet, weigh up to several tons, and live for two hundred years.The saguaro's sharp spines protect it from harm. The accordion-like pleats in its skin expand in the rain, storing extra water for the long dry times.There are many kinds of animals in this desert.The desert holds such animals as the gobi bear, ibex and the black-tailed gazelle. Wild and domesticated animals (camels, horses, asses and gazelles) roam together on the steppes.