Surprisingly, some deserts around the world actually have lakes. The best advice if you ever find yourself stranded in these deserts and come across one of these lakes is to avoid drinking it for nourishment as most are salt lakes. While a few desert lakes are permanent, most of them are only temporarily available.
One of the mysteries of the desert that remained unexplained the longest was the presence of a filmy material similar to lacquer found on cliffs and rocks. This material is now called desert varnish and has been found to be a thin layer of metallic oxide deposited on surfaces and then burnished by sand that regularly blows over it.
One thing found in cold deserts rather than hot deserts is permafrost. This refers to a layer of permanently frozen ground that can penetrate as deeply as 2,000 feet in Siberia, but typically averages only half that.
Plants called living stones grow in the sand of deserts, exhibiting on the surface only a small portion through which light can enter. A walk through a desert may result in confusing these living organisms with small pebbles or rocks. Some living stones are almost impossible to discover until they have flowered.
Acacias are the most common type of tree found in arid deserts. These trees are notable for their characteristic umbrella shape that efficiently catches what little water may drop from the sky. If the rainy season fails to produce enough water to sustain the tree, the acacia tree's leaves droop and fall. New leaves will then be produced the next year.
Various types of cacti can thrive in torrid desert conditions because of their ability to store water in their leaves or stems. Cacti come in a variety of sizes and shapes that can range from small but wide Golden Barrel cactus to the tall and narrow Saguaro that is such an iconic part of the Sonoran Desert.
The Sand Cat is the only cat that can be found almost exclusively living in sandy deserts. These small cats rarely make it to ten pounds and escape the punishment of the desert heat by burrowing into the sand and doing its hunting during the cooler nighttime hours.
Penguins are a recognizable inhabitant of the cold Antarctic Desert. These flightless water fowl have evolutionarily adapted to survive without the ability to fly as well as to thrive in extreme weather conditions. While penguins waddle on the land at a leisurely pace, they can swim underwater at high speeds with a level of mobility that makes it look more like they are flying than swimming.
