A hardy, woody and perennial plant without buds is called a shrub. For example – Rose, Jaba, Dhutura, Rangan, Basak etc.

A plant smaller than a shrub is called an under shrub. For example – Dadmardan, Kalkasunda etc.

Perennial plants with small and soft stems are called herbs. For example – paddy, wheat, Bhutra, Raktdrona, Shwetdrona, Durbaghas etc.

1. Herbaceous: Perennial plants with small and soft stems are called herbs. For example – paddy, wheat, Bhutra, Raktdrona, Shwetdrona, Durbaghas etc.
2. Under Shrub: A plant smaller than a shrub is called an under shrub. For example – Dadmardan, Kalkasunda etc.
3. Shrub: A hardy, woody and perennial plant without buds is called a shrub. For example – Rose, Jaba, Dhutura, Rangan, Basak etc.
4. Tree: Hard, woody and perennial plants with buds are called trees. Like- Mango, Jam, Jackfruit etc. Dr. Siddique Publications
5. Epiphyte: A plant that grows under the shelter of other plants but does not absorb food is called paraphyte. For example, orchids
6. Parasites: Plants that grow on other green plants and take food from them are called parasites. For example, golden vine.
7. Saprophytes: Plants that grow on dead plant or animal bodies and take food from them are called Saprophytes. Eg Agaricus, Mucor, Penicillium, Saprolegnia etc.

About 1000 species of herbaceous plants are of economic importance. Among them, 100 species are of international commercial importance.
1. As food: 80% of human food needs are met by only 20 types of herbaceous plants. 15 species are used as staple food all over the world. Out of these 4 species rice, wheat, bhutra and sugarcane meet 63% of human sugar requirement. Rice is the staple food of 60% of the world’s people. 35% of people’s staple food is wheat or bread.
2. Livestock feed: Thousands of species of grasses are the main food of domestic animals like cow, buffalo, goat, sheep etc.
3. Sugar production: Sugar is produced from sugarcane. Various food items are made from sugar.
4. Aromatic Cosmetics: Aromatic oils and cosmetics are made from lemon grass.
5. Preparation of medicines: 120 types of modern and valuable medicines are made from more than hundred species of plants.
6. As a herb: Durbaghas is used as an herb to stop bleeding and heal wounds.
7. Paper making: Paper is made from bamboo, reeds and sugarcane.
8. Fuel: Roots, stems and leaves of plants are used as fuel.
9. Construction Materials: Bamboo and wood are used as construction materials.
10. Industry: Bread, biscuits, alcohol, vinegar etc. are made from plants.
11. Beautification: Flowering plants are planted in houses, roads and gardens to enhance beauty.
12. Weeds: Weeds grow in cropland causing great damage to crops.

Liliopsida consists of 4 sub-classes, 20 classes and 65 genera. The sub-classes are:
(i) Alismatidae: Class number of Alismatidae is 3.
(ii) Lilidae: Class number of Lilidae is 3.
(iii) Arecidae: The class number of Arecidae is 5.
(iv) Commelinidae: The class number of Commelinidae is 6.

Magnoliopsida consists of 7 sub-classes, 56 classes and 315 genera. The sub-classes are:
(i) Magnolidae: The class number of Magnolidae is 7.
(ii) Hamamelidae: Class number of Hamamelidae is 8.
(iii) Ranunculidae: The class number of Ranunculidae is 3.
(iv) Caryophyllidae: The class number of Caryophyllidae is 3.
(v) Dillenidae: The class number of Dillenidae is 12.
(vi) Rosidae: Class number of Rosidae is 16.
(vii) Asteridae: Class number of Asteridae is 7.

The class of herbaceous plants is Magnoliophyta. Magnoliophyta are divided into two classes. Magnoliopsida and Liliopsida.
1. Magnoliopsida: Magnoliopsida consists of 7 sub-classes, 56 classes and 315 genera. The sub-classes are:
(i) Magnolidae: The class number of Magnolidae is 7.
(ii) Hamamelidae: Class number of Hamamelidae is 8.
(iii) Ranunculidae: The class number of Ranunculidae is 3.
(iv) Caryophyllidae: The class number of Caryophyllidae is 3.
(v) Dillenidae: The class number of Dillenidae is 12.
(vi) Rosidae: Class number of Rosidae is 16.
(vii) Asteridae: Class number of Asteridae is 7.
2. Liliopsida: Liliopsida consists of 4 sub-classes, 20 classes and 65 genera. The sub-classes are:
(i) Alismatidae: Class number of Alismatidae is 3.
(ii) Lilidae: Class number of Lilidae is 3.
(iii) Arecidae: The class number of Arecidae is 5.
(iv) Commelinidae: The class number of Commelinidae is 6.

1. Herbaceous plants are shrubs, trees and shrubs. Some plants are parasitic or parasitic in nature. Siddique Publications
2. The main plant body is the sporophyte. They are of the most advanced nature.
3. Plant bodies can be soft or hard, woody or non-woody, evergreen or deciduous, annual or perennial.
4. They are flowering plants. The flowers of the plant are solitary or in panicles.
5. They are vascular plants. Vascular bundles are connected and anterior. Free and Equilateral or Equilateral.
6. The uterus is divided into uterus, uterus and cervix.
7. The germinated pollen grains fall into the ovary.
8. Their uterine chambers are special. Ovulation is produced in it.
9. The seeds are enclosed inside the fruit.
10. Seeds contain one or two carpels.
11. Their spermatozoa are non-flagellate and motile.
12. They are bisexual.
13. Their seeds are triploid and produced after fertilization.
14. Xylem contains vessels and phloem contains cells.
15. They do not produce archegonia, so are advanced in nature.
16. Gametophyte is very short and dependent.
17. The life cycle has a clear sequence.
18. 120 kinds of modern and valuable medicines are prepared from more than hundred species of plants.

The world’s smallest herbaceous plant is Wolffia microscopy. Its length is 0.1 mm or 300-600 micrometers and weight is 150 micrograms. The tallest herbaceous plant is Eucalyptus marginata. Its height is 500 feet. It is found in Tasmania, Australia. The smallest herbaceous plant of Bangladesh is Wolffia arrhiza (duckweed). There are 2,87,000 species of plants in the world. However, the number of species in Bangladesh is about 5000.
Herbaceous plants are believed to have originated in the Cretaceous period 13 million years ago. The first herbaceous plants originated in tropical regions, particularly Southeast Asia. Spread in different directions within 4-5 crore years. No fossils of herbaceous plants have been found till date.