a pair of plant stipules

例句：

1. 1. The plant hasa pair of stipules atthe top of its stem.
   这植物的茎顶部有一对叶柄。
2. 2. The scientiststudied the structure of the plant'sstipules to understand its growthpatterns.
   科学家研究了这种植物的叶柄结构，以了解其生长模式。
3. 3.The stipules are used asa natural insect repellent bysome plants.
   某些植物的叶柄被用作天然的驱虫剂。