What types of leaves are found in deserts?

In desert plants, the leaves are modified into spines-like structures to prevent water loss through transpiration.

[Extra information for reference: 

Desert plant-like Cactus adapted to survive in a desert with its specific features such as:

a) The long roots that can go deep in the soil for the absorption of water.

b) The leaves are modified into spines to prevent water loss through transpiration.

c) The stem is covered with a thick layer of wax to retain water.

The desert plants make their food by photosynthesis. The stomata of desert plants are closed during the daytime to prevent transpiration and conserve water. The stomata conduct a gaseous exchange at night. The carbon dioxide entered the leaf during the daytime.

Photosynthesis takes place during the daytime. The intermediate product is stored into a vacuole which is sent to the stroma of chloroplast during the daytime. It gets broken down into carbon dioxide and pyruvate. This carbon dioxide enters into the Calvin cycle.]