Onion epidermal cells under microscope.
The outline of plant epidermal cells is polygonal [for example, Selaginella, Cycas, Rhodiola japonica, Grape, etc.]. ]; Some are wavy [such as Sedum, Solanaceae, Gramineae]; Some are slender spindles [such as iris peach leaf and iris rubra]. The cell wall facing outward is usually thick, or there is a layer of cellulose and keratin outside the cell wall, and there is a stratum corneum outside this layer. The cuticle is developed, such as the leaves of Clivia and the peel of apple, and the surface is shiny. Others secrete wax on the surface, which is called wax film. This wax is granular, rod-shaped or flat, and is mixed in the stratum corneum. Cell wall of equisetum alpinum. Japanese elm, American elm and beech contain silicic acid crystals. Stalactites are found in epidermal cells such as nettles and Arnebia euchroma. Anthocyanin.