The formation of wood results from secondary growth. Plant Tissues . The epidermis is a dermal tissue. In roots, epidermal cells may give rise to root hairs. Epidermal cells of leaves and young stems have cuticles on their external surface to avoid desiccation.
Some plants also have hairs or trichomes .
Sclerenchyma tissue consists of sclereids and fibers , which have thick secondary cell walls and are typically dead at maturity. Their main function is to provide support. Sclereids can have many different forms and occur throughout the plant. Fibers in contrast, are thin and elongated cells usually associated with vascular tissues. The two main vascular tissues are the xylem and phloem.