1.Acropetal differentiation of the cambium layer continues as the primary root elongates.

1.形成层的向顶分化像初生根伸长一样进行。

2.Interfascicular cambium A single layer of actively dividing cells between the vascular bundles in stems.

2.束间形成层是于茎的维管束间的有盛分裂能力的一层细胞。

3.Bark The outermost tissue of the stem and roots in woody plants, on the outside of the phellogen (cork cambium).

3.木本植物中的茎或根中木栓形成层外方的全部组织，称为树皮。