Stomata in grass leaf are

In grasses, the guard cells are dumb-bell shaped.

In grasses, the guard cells that surround the stomata have a distinctive dumb-bell shape, which is different from the more common kidney or bean-shaped guard cells found in many other plants. This unique shape plays an important role in the function of the stomata, which are small openings on the surface of leaves and stems that allow gases, such as carbon dioxide and oxygen, to pass in and out, while also helping in the regulation of water vapor.

The dumb-bell shape of the guard cells in grasses helps them to open and close the stomata efficiently. The cells are asymmetrical, meaning one side is thicker than the other, allowing the cells to bend and swell in a way that changes the size of the stomatal pore. When the guard cells absorb water, they become turgid (swollen), causing the stomata to open, and when they lose water, they become flaccid (soft), causing the stomata to close. This regulation is crucial for balancing gas exchange and controlling water loss, especially in grass species that often grow in areas with varying water availability.

The specific shape of the guard cells in grasses allows for precise control of stomatal aperture, which contributes to the plant's ability to adapt to different environmental conditions.