01.PLANT DIVERSITY.

1.1 Morphological features of floweringplants

* There are two types of plants.

1. Flowering plants

2.Nonflowering plants

*Plants which produce flowers are called flowering plants.

*Plants which do not produce flowers are called nonflowering plants.

Examples for flowering plants- Rose, Idda , Lotus, Curryleaves , Katorolu , Long bean,

Examples for nonflowering plants- Cycus , Moss , Ferns, Cyperus , Salvinia ,Drynaria

Flowering plants

Nonflowering plants

1.2 Main parts of the floweringplant.

01. tap root

02. lateral roots

03. root system

04. stem

05. lateral buds(axillary buds)

06. leaves

07. apical bud

08. branches

09. fruits

10. flowers

11. shoot system

1.3 Diversity of the parts of flowering plants

Diversity among roots

* There are two types of root systems.

1. Tap root system

2. Fibrous root system

Some plants have a single large root which orginates from base of the stem. It is called the tap root. Large number of roots are orginated from the tap root. They are called lateral roots. this type of root system is called as tap root system.
Some plants have large number of roots which are orginated from base of the stem. This type of root system is called as fibrous root system.

Functions of roots of plants

* Fix the plant to the soil.

* Absorb water and minerals dissolved in water ( absorption)

* Give rise to new plants by vegitative propagation.

e.g.:- Curry leaves, 'Beli'/ 'Vilvam', Bread fruit

Types of roots.

1. Roots with root nodules

These structures can be seen in mimosa plant.
There are micro organisms called bacteria live inside them.
This bacteria supply nitrogen required to the growth of the plant.
We can see these root nodules in legume plants.

2. Storage roots

Food can be stored in these roots.
Such roots are storage roots.

3. Aerial roots

We can see these roots in orchid.
Function- Absorb water vapour from the atmosphere.
Some aerial roots carryout photosynthesis.
They are green in colour.

3. Prop roots

We can see these roots in Banyan.
Function- Support the branches.

4. Stilt roots

We can see these roots in pandanus plant.
Function- Support the stem.

5. Climbing roots

We can see these roots in betel and pepper.
Function- Helps to climb the stem by attaching to another system.

6. Respiratory roots

We can see these roots in kadol.
Function- Exchange of air with the atmosphere.

Diversity among stems

* There are two types of stems.

1. brached stem

2. unbranched stem

Functions of plant stem

Bears flowers,leaves,buds,fruits and seeds.
Supports the plant by keeping rigid.
Transport water and food.
Produce new plants by the stems.(vegetative propogation)
Some plants with green colour stems carryout photosynthesis.

Eventhough most stems grow above the soil, some stems grow inside the soil. They are called underground stems.

Diversity of leaves

*Common parts of a leaf

Leaf venation

Reticulate venation
Parallel venation

Simple and compound leaves

When the leaf blade of a leaf is not divided into segments it is called a simple leaf.

e.g.:- Shoe flower, Jak

Leaf blade of a compound leaf is commpletly divided into small leaf like parts called leaflets. These types of leaves with leaflets are called compound leaves.

e.g.:- Coconut, Tamarind

Functions of plant leaves

The main function of a plant leaf is photosynthesis. Through photosynthesis plants produce food in leaves.
Some leaves are adapted to store water.
Some leaves produce new plants.

Parts of a dlower and diversity of flowers.