Anatomy of Flowering Plants

## Anatomical differences between monocot root and dicot root

| Feature | Dicot root | Monocot root |
|---|---|---|
| Xylem bundles | Usually 2 to 4 (few) | Usually more than 6 i.e. polyarch |
| Pith | Small or inconspicuous | Large and well developed |
| Secondary growth | Present in many dicot roots | Absent |
| Conjunctive tissue | Present between xylem and phloem | Present, but root remains primary and does not show secondary growth |

### Main identifying points
- In a dicot root, xylem and phloem are fewer in number, and the pith is small.
- In a monocot root, xylem bundles are many and the pith is large.
- Secondary growth occurs in dicot roots but not in monocot roots.

### Simple labelled sketch points
- Outer epiblema with root hairs
- Cortex
- Endodermis with Casparian strips
- Pericycle
- Xylem and phloem
- Pith (small in dicot, large in monocot)

## Anatomical differences between monocot stem and dicot stem

| Feature | Dicot stem | Monocot stem |
|---|---|---|
| Hypodermis | Collenchymatous | Sclerenchymatous |
| Vascular bundles | Arranged in a ring | Scattered in the ground tissue |
| Cambium | Present in vascular bundles | Absent |
| Type of vascular bundles | Conjoint, open | Conjoint, closed |
| Phloem parenchyma | Usually present | Absent |
| Bundle sheath | Not a prominent feature | Each bundle surrounded by a sclerenchymatous bundle sheath |
| Pith | Large and distinct | Ground tissue large and conspicuous; distinct pith not well separated |
| Secondary growth | Usually present | Usually absent |

### Main identifying points
- A dicot stem has vascular bundles in a ring and each bundle is open because cambium is present.
- A monocot stem has scattered vascular bundles, each with a sclerenchymatous bundle sheath, and bundles are closed.

### Simple labelled sketch points
- Dicot stem: epidermis, collenchymatous hypodermis, cortex, endodermis, pericycle, ring of vascular bundles, pith
- Monocot stem: epidermis, sclerenchymatous hypodermis, scattered vascular bundles with bundle sheath, large ground tissue

The given features are:
- conjoint, scattered vascular bundles
- surrounded by sclerenchymatous bundle sheaths
- phloem parenchyma absent

These are the characteristic features of a monocotyledonous stem.