Plant Kingdom

Plant Kingdom

There are millions kind of plant found on the earth. Plants are unicellular, microscopic to well-developed multicellular huge trees. On the basis of presence or absence of flowers, all the plants are divided into two major sub-kingdoms. They are: Cryptogams and Phanerogams.

Cryptogams:

Cryptogams are primitive and simplest plants. They do not bear flower. On the basis of their appearance and the stage of development, cryptogams are divided into three divisions. They are: Thallophytic, Bryophyte and Pteridophyta.

Phanerogams:

All kind of flowering and seed-bearing plants are called Phanerogams. Its division called spermatophyte as it contains seed bearing plants. It is further divided into two sub-division which are: Gymnosperm and Angiosperms.

Gymnosperm:

Gymnosperms are the corn bearing plants. They possess the following features.

·         They grow in dry land are ever green shrubs or trees but not herbs. They have naked seeds i.e. seeds are not enclosed in fruits.

·         Plants are monoecism as they bear male and female cone in the same plant.

·         Usually they contain both foliage and scale leaves.

·         Pollination takes place by wind. Example: Pinus, Cycas, etc.

Angiosperm:

Angiosperm possesses the following features.

·         They may be annual or perennial and grow on both land and water.

·         They may be herb, shrubs, and trees.

·         They bear flowers.

·         Their seeds are enclosed in true fruits.

·         Most of the Angiosperms are bisexual while some of them are unisexual.

On the basis of cotyledons in their seeds Angiosperms are further divided into two classes. They are monocotyledon and dicotyledonous.

Monocotyledons:

This class includes many plant species which are very widely distributed throughout the world. They are those plants which have only one cotyledon in their seed. The general characteristics of monocotyledon are as follows:

·         Monocot plant bears single cotyledon in their seed.

·         They have fibrous root system.

·         They have long and narrow leaves with parallel venations.

·         Stem contains scattered vascular bundles.

·         They have no woody system. Examples: bamboo, grass, sugarcane banana, lily, wheat, rice, maize, palm, onion, garlic, barley etc.

Dicotyledonous:

It contain very large and distinct group of plants in the world. The general characteristics of dicotyledonous are as follows:

·         Dicots bear two cotyledons in their seeds.

·         They have tap root system

·         Stem contains vascular bundles which are arranged in rings.

·         Usually they have bored leaves with reticulate venations.

·         Examples: peas, mustard, gram, mango, bean, peepal etc.