What are bulliform cells?

Bulliform cells are specialized, large, bubble-shaped epidermal cells found primarily in the leaves of certain plants, particularly in monocots like grasses. These cells play a critical role in regulating water loss through transpiration. Under dry conditions, bulliform cells can collapse, which causes the leaf to fold or roll. This folding reduces the surface area exposed to the sun and air, thus minimizing water loss. When water is abundant, these cells expand and help the leaf return to its flat state, maximizing photosynthesis. This adaptive feature is vital for plant survival in arid environments, making the understanding of bulliform cells crucial in the study of plant physiology and ecology.