Image: leaf of an oak stained with safranin / Alcian blue. The central vein (rounded structure) and part of the leaf are shown.
Epidermis: it is the outermost layer of the leaf. The epidermis consists of cells with non-lignified cell walls because it is a young leave. However, a thick cuticle is observed at the free surface of the epidermal cells.
Cuticle: it is a layer of waxes and cutin lining the free surface of the epidermal cells. Cuticle is a protecting layer against dehydration and mechanical insults.
Palisade parenchyma: it is the parenchyma found near the upper part of the leaf. Palisade parenchyma is photosynthesizing parenchyma with cells oriented perpendicularly to the epidermis, tightly packaged, and containing many chloroplasts. The palisade parenchyma forms part of the mesophyll, which is the parenchyma tissue between the top and the bottom epidermal layers.
Spongy parenchyma: it is the parenchyma found near the blower part of the leaf. Spongy parenchyma is made up of parenchyma cells with large empty intercellular spaces. Together with the palisade parenchyma, the spongy parenchyma forms the mesophyll, which is the tissue between both epidermal layers.
Stoma: they are epidermal structures consisting of specialized cells that form a pore for gas and water exchange between the parenchyma and the environment. Stomata are mainly found in the lower epidermal surface of the leaf.
Sclerencnhyma: the vascular bundles of the leaf are surrounded by la sheath of sclerenchyma fibers for mechanical support. los haces vasculares del nervio principal están rodeados externamente por una vaina de esclerénquima.
Phloem: it is the vascular tissue specialized in the uptake of the photosynthesized molecules in the leaf. It is primary phloem made up of small cells with cell walls stained in blue.
Xylem: it is the vascular tissue specialized in bringing water for photosynthesis. It is primary xylem consisting of large cells with thick cell walls stained in red.