Describe the modifications of the stem for photosynthesis.

(N/A) In some plants of arid regions,the stems become flattened (e.g.,$Opuntia$) or fleshy cylindrical (e.g.,$Euphorbia$) structures. They contain chlorophyll and are capable of performing photosynthesis. These modified stems are known as $Phylloclade$. Examples include $Opuntia$,$Euphorbia$,and $Muehlenbeckia$.