cambium
noun [ C or U ] biology specialized uk/ˈkæm.bi.əm/ us/ˈkæm.bi.əm/ cambiums or cambia /ˈkæm.bi.ə/ /ˈkæm.bi.ə/
形成层（木本植物根部和茎部的细胞层，其通过细胞分裂形成新的木质部和韧皮部）
a layer of cells in the roots and stems of some plants that divide to produce new tissue, such as xylem and phloem