Lateral roots are un-tapered, rope-like roots that grow outward from the main root and form a network to support the tree. They also help the tree to absorb water and nutrients from the soil. Lateral roots can grow very long and wide, sometimes reaching two to three times the size of the tree's crown. Lateral roots are formed by the pericycle cells, which are located inside the endodermis layer of the root. The pericycle cells develop into lateral root primordia (LRP), which then break through the outer layers of the root and grow into the soil. Lateral roots are common and abundant in many tree species, such as oaks, walnuts, hickories, black gum, sassafras, sweet gum, Japanese pagoda, butternut, pines and hornbeam.