Acropetal differentiation of the cambium layer continues as the primary root elongates . 形成层的向顶分化像初生根伸长一样在继续进行。
2.
In the early december , the first bract primordium was formed in the axil scale at the cone base , then bract initiation had occurred in acropetal direction 12月初，最初的苞片原基在雌球果原基的鳞片的叶腋处产生，之后其由基部向顶部连续发生。
3.
Acropetal describing a process ( such as growth or development ) that progresses from the base or boint of attachment , so that the oldest parts are at the base and the youngest are at the tip 向顶：描述植物器官生长或者发育的一个过程，这个过程是自下而上的，因此较年老的部分在底端，而幼小的部分在顶端。
