劍橋詞典a layer of cells in the roots and stems of some plants that divide to produce new tissue , such as xylem and phloem 形成層（木本植物根部和莖部的細(xì)胞層，其通過(guò)細(xì)胞分裂形成新的木質(zhì)部和韌皮部） 返回 cambium