stem mother

例句：

1. 1. The tree's stem is green and strong.
   这棵树的树干是绿色的，很强壮。
2. 2. The stem of the plant is covered in soft hairs.
   这种植物的茎上覆盖着柔软的毛。
3. 3. The stem of the flower has a sweet smell.
   花朵的茎有一股甜甜的味道。