exodermis
noun [ S ] biology specialized uk/ˌek.səˈdɜː.mɪs/ us/ˌek.səˈdɝː.mɪs/
（植物根部的）外皮层
a layer of cells in a plant's root underneath the epidermis (= outer layer)
The exodermis is thought to protect against water loss from the root to the soil. 人们认为，外皮可以防止水分从根部流失到土壤中。
- More examples
- The cells of the exodermis are very compact, restricting the flow of water.
- The exodermis is a single-cell layer at the outer surface of the root directly below the root epidermis.
- The exodermis of a one-year-old root is often flaking and falling off.