sepalulum

例句：

1. 1.The flower's sepalum are delicate and colorful.
   这朵花的花瓣很精致且色彩斑斓。
2. 2. The sepalum of the rose is a symbol of love.
   玫瑰的花瓣是爱情的象征。
3. 3. The sepalum of the orchid is used for medicinal purposes.
   兰花的花萼被用于药用。