Angiosperm

Angiosperms, commonly known as flowering plants, encompass a vast group of plants characterized by the presence of flowers and fruit. They are the most diverse group of land plants and include everything from herbs and shrubs to trees. Angiosperms are distinguished from gymnosperms by characteristics such as flowers, endosperm within the seeds, and the production of fruits that contain the seeds.

Characteristics

Angiosperms are defined by several key characteristics:

• Flowers: The presence of flowers is the most distinctive feature of angiosperms. Flowers facilitate pollination and are the reproductive structures of these plants.
• Fruits: Following pollination, the fertilized flowers of angiosperms develop into fruit, which encloses the seeds.
• Endosperm: This is a tissue produced inside the seeds of most angiosperms, which nourishes the developing embryo.

Classification

Angiosperms are classified into two main groups:

• Monocots: Characterized by having one seed leaf, or cotyledon, parallel veins in the leaves, and flower parts typically in multiples of three.
• Eudicots: Most have two cotyledons, net-like veins in the leaves, and flower parts usually in multiples of four or five.

Evolution

The origin of angiosperms has been a subject of international research and debate. It is generally believed that they first appeared at least 140 million years ago, during the Cretaceous period, and rapidly diversified. The rapid diversification of angiosperms has been one of the major reasons for the dominance of terrestrial ecosystems.

Ecological and Economic Importance

Angiosperms are crucial for the ecological balance and the economy. They provide habitat, food, and oxygen and are also sources of products such as timber, medicine, and fibers. Furthermore, angiosperms are essential for the survival of many animal species, providing food and shelter.

See also

• Plant morphology
• Pollination
• Seed dispersal