SCIENCE! :): Plants in the Desert

1) Saguaro

-The saguaro grows on the northern and southern slopes of the Sonoran Desert.

-It grows in gravel and rocky soils, usually between he heights of 610 to 1068 meters.

-extracts water from its environment every chance it gets

-Its roots are 2.5 centimeters deep in the soil, so it can soak up as much rain and dew before it evaporates. A giant saguaro can soak up to a ton of water during a heavy rain.

-has a spongy inside layer that helps distribute water in the plant. Its outside skin is pleated, so

when more water is absorbed its outside can expend to make room.

-Growth is very slow (can take thirty years or more before the saguaro can reach 1.5 meters high. After eighty years pass, the plant can be 6 meters tall and still not be full-grown. Two centuries may pass before the plant reaches its mature height)

-By growing slowly, the saguaro expends less energy, food, and water, making it fully adapted to the desert.

2) Living stones (Lithops)

-most of the plant’s leaf surface below the ground

-It is cooler; there is less exposure to drying winds, and less chance of being spotted by a grazing animal.

-Gas exchange occurs underground. The stomata open without any exposure to wind or sun, so water loss is minimized during this process.

-limited amount of leaf surface area exposed to the sun for photosynthesis to supply food for the plant.

-The clear tips of the leaves have a crude optical system that permits light striking the windows to be diffused by crystals of calcium oxalate onto the green photosynthetic area below

-seed capsules will not open to disperse their long-lived seeds until they experience rainfall or heavy dew

3) Joshua Tree