Desert plants are adapted to drought :
They gather water through their roots, which either spread out near the surface to soak up drew or grow deep down to moist soil layers.
The biggest cactus is the sonoran
Desert in south-west usa. It can grow 15 meters high.
Desert plants often have bright beautiful flower that only appear for a short time after rain has fellen. 
They don't live long,so they must attract pollinating insects quickly. That is why their petals are so colourful.