Angiosperms: Characteristics, Classification, and Importance, Slides of Botany and Agronomy

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Angiosperms

Angiosperms are flowering plants.

• They have true roots, stems, leaves and flowers...
• Angiosperms are more highly evolved that the algae, mosses, fungi and ferns.

• Traditionally, the flowering plants have been divided into two major groups, or classes : The

Eudicots (dicot) and the Monocots

• Monocot- single cotyledon
• Eudicot- true two cotyledon

Chars of Angiosperm

Cotyledons – The cotyledons are the "seed leaves" produced by the embryo.

They serve to absorb nutrients packaged in the seed, until the seedling is able to produce its first true leaves and begin photosynthesis.

Number of flower parts --

• If you count the number of petals, stamens, or other floral parts, you will find that monocot flowers tend to have a number of parts that is divisible by three, usually three or six.
• Dicot flowers on the other hand, tend to have parts in multiples of four or five (four, five, ten, etc.).
• This character is not always reliable, however, and is not easy to use in some flowers with reduced or numerous parts.

The flower

Stem vascular arrangement --

• Vascular tissue occurs in long strands called vascular bundles.
• These bundles are arranged within the stem of dicots to form a cylinder, appearing as a ring of spots when you cut across the stem.
• In monocots, these bundles appear scattered through the stem, with more of the bundles located toward the stem periphery than in the center.

This arrangement is unique to monocots and some of their closest relatives among the dicots.

Root development --

• In most dicots the root develops from the lower end of the embryo, from a region known as the radicle.
• The radicle gives rise to an apical meristem which continues to produce root tissue for much of the plant's life.
• By contrast, the radicle aborts in monocots, and new roots arise adventitiously from nodes in the stem. These roots may be called prop roots when they are clustered near the bottom of the stem.

Angiosperms

• primary food source
• oxygen for us to breathe.
• lumber for buildings
• fibers for clothes
• basis for many drugs, etc

Monocots

Flowers and fruit of the banana

Rice

Inflorescences