Name one structure which is very distinct in roots but poorly developed or even absent in stems.

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for a structure that is prominent in roots but either poorly developed or absent in stems.

2. **Identifying the Structure**: The structure that fits this description is the **endodermis**.

3. **Defining the Endodermis**: The endodermis is the innermost layer of the cortex in roots. It is composed of tightly packed living cells.

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