(i) Upper layer: The upper layer of the sheet is called upper layer. It is composed of single cells. Cuticles are present on the surface.
(ii) Hypodermis: The hypodermis is composed of unicellular cells. At the bottom there are tiny sporangia along the edges. Spores are produced inside the sporangium. At the base there is a leaf pore.
(iii) Mesophyll tissue: Mesophyll tissue is present in the middle of both skins. It is composed of spongy and palisade parenchyma. Parenchyma cells contain chlorophyll and have air cavities. Its steely hydrocentric.