The layers below the epidermis in aerial parts of the dicotyledonous plants is made of cells that

The collenchyma occurs in layers below the epidermis in most of the dicotyledonous aerial plant parts. It consists of cells whose cell walls are much thickened at the corners due to a deposition of cellulose, hemicellulose and pectin. They provide mechanical support to the growing parts of the plant such as young stem and petiole of a leaf.