Root Modification Types
Key Facts:
- Tap root system = 1 primary root + laterals → Dicots (carrot, radish, mustard)
- Fibrous/Adventitious root = many roots from base of stem → Monocots (grass, rice, wheat)
- Prop roots: from aerial branches → downward into soil
- Stilt roots: from lower stem nodes → oblique support (Maize, Sugarcane)
- Pneumatophores: grow upward (negatively geotropic) for gaseous exchange
Critical Distinction Table:
| Root Type | Example | Origin | Direction | Function |
|---|---|---|---|---|
| Prop root | Banyan | Aerial branches | Downward | Support |
| Stilt root | Maize | Lower nodes | Oblique | Support |
| Pneumatophore | Rhizophora | Submerged roots | Upward | Gas exchange |
| Tuberous adventitious | Sweet potato | Adventitious | Varied | Food storage |