carpule

例句：

1. 1. The carpule is the part of a tree trunk that contains the heartwood.
   心材是树的树干部分，包含心材。
2. 2. The carpule is often used to describe the innermost layer of wood in a tree trunk.
   心材通常用来描述树根内部最内层的木材。
3. 3. The carpule is also known as the heartwood, which is the most durable and valuable part of the tree.
   心材也被称为心木，这是树木中最耐用和最有价值的部分。