A layer of parenchyma cells surrounding each vein in leaves is called as

Border parenchyma (also called bundle sheath extension) is a specialized layer of parenchyma cells that surrounds each vascular bundle in leaves. This layer connects the vascular bundle to both the upper and lower epidermis, facilitating transport and providing mechanical support. Palisade and spongy parenchyma are the main photosynthetic tissues, while chlorenchyma is a general term for chlorophyll-containing parenchyma.