trophophyll

例句：

1. 1. The trophophylls are the protective outer layers of aflower.
   花萼是花朵的保护外层。
2. 2. Thetrophophylls are oftenused in botany to describe the structureof flowers.
   花萼在植物学中常用于描述花朵的结构。
3. 3. Thetrophophyllsare also known as calyxes in some botanicaltexts.
   在某些植物学文本中，花萼也被称为花冠。