Stem modification found in plants growing in arid regions where the stem is modified to green flattened or cylindrical fleshy structures with several nodes and internodes which help in photosynthesis is:

Some plants of arid regions modify their stems into fleshy flattened (Opuntia), or fleshy cylindrical (Euphorbia) structures. They contain chlorophyll and carry out photosynthesis. Such stem modifications are called phylloclades.