Division Angiospermophyta ( Flowering Plants )

Angiosperms are divided into two major groups:

1. Monocotyledonous plants (monocots)

These are flowering plants whose seeds contain one cotyledon (seed leaf).

2. Dicotyledonous plants (dicots)

These are flowering plants whose seeds contain two cotyledons (seed leaves).

Angiosperms reproduce through specialized organs called flowers, which have the following parts:

1. Sepals: Protect the flower bud before it opens.
2. Petals: Often colorful and scented to attract pollinators.
3. Stamen (Male Part):
   1. Anther: Produces pollen grains (male gametes).
   2. Filament: Holds the anther.
4. Carpel (Female Part):
   1. Stigma: Receives pollen.
   2. Style: A tube that connects stigma to ovary.
   3. Ovary: Contains ovules which develop into seeds after fertilization.

1. Flowers as Reproductive Structures: Flowers contain both male and female organs.
2. Bisexual Flowers: Have both stamens and carpels in the same flower (e.g., flamboyant tree).
3. Unisexual Flowers: Male and female organs are found in separate flowers (e.g., maize).
4. Enclosed Ovules: Ovules are enclosed within the ovary, forming seeds after fertilization. The ovary matures into a fruit.

Angiosperms show vast diversity in form, size, and habitat:

1. They include woody plants (e.g., coconut trees) and non-woody herbs (e.g., maize).
2. Range from small herbs (e.g., groundnuts) to large trees (e.g., baobab).
3. Grow in terrestrial and aquatic environments.

1. Timber Production: Source of construction wood and furniture.
2. Fuel: Used for charcoal and firewood.
3. Paper Manufacturing: Trees like eucalyptus are used in making paper.
4. Medicinal Use: Some species produce medicines (e.g., neem, foxglove).
5. Decoration: Flowers are widely used for decoration.
6. Industrial Uses: Produce materials like rubber, tannins, and plastics.
7. Soil Fertility: Provide organic manure through decomposition.
8. Resin Production: Source of commercial resins.

1. Allergies: Pollen from flowers may cause allergic reactions.
2. Oxygen Competition: Indoor potted plants may compete for oxygen at night.
3. Toxicity: Some species are poisonous (e.g., improperly prepared cassava).