Question

how does desert plants control the loss of water from their body

Answer 1

They have capability to store water even in high temperature.

Answer 2

Less leaf surface area results in reduced water loss through the epidermis. Small leaves have fewer stomata than larger leaves, and that adaptation also reduces water loss. Some dry-land plants have stomata only on the bottom epidermis, which further reducing water loss, and some have several layers of epidermal cells.