What adaptations does this plant have to thrive in a dry, arid climate?

Xerophytes, such as cacti, usually have special means of storing and conserving water. They often have few or no leaves, which reduces transpiration. Phreatophytes are plants that have adapted to arid environments by growing extremely long roots, allowing them to acquire moisture at or near the water table.

Hope this helps you

- Nila

b.have there own function.