epitropous ovule

例句：

1. 1. The epitropous ovule is the first stage of a flower's development.
   胚珠是花发育的第一阶段。
2. 2. In plants, the epitropous ovule is the female reproductive structure that develops into a seed.
   在植物中，胚珠是雌性生殖结构，发育成种子。
3. 3. The epitropous ovule is responsible for the formation of the plant's seeds and pollen.
   胚珠负责形成植物的种子和花粉。