How many types of plants are …

Classification of plants 
1) Based on the size, nature of the stem and the life span, plants are classified into herbs, shrubs and trees There is one more category called as creepers and climbers.
a) A herb is a non-woody plant that has green and tender stem with few branches on. It is usually short. It has a very short life.

• Mustard, Tulsi, Wheat, Gram are some of the herbs we know.

b) A shrub is taller than a herb and has stem branching out at its base. Shrub is a bushy plant. The stems of a shrub are not hard but thick.

• Sunflower, Rose, Lime are some of the shrubs that we see around. 

c) A tree is a woody plant that has many branches on a single stem. Trees serve us lot of benefits. Trees are with long life span.  

• Mango tree, Neem tree, Peepal tree are some of the trees in our surroundings.

d) Creepers are the plants with weak stems and hence cannot stand straight. They grow on the ground. Creepers as the name suggests creep horizontally on the ground. Life time of creepers if very short.

e) Climbers are the plants that need support from other structures to grow and spread. Climbers can either grow horizontally or vertically unlike creepers that grow only in horizontal direction. Lifespan is very short in climbers.

2) Depending on the presence of flowers, plants are classified into two types namely, flowering plants and non-flowering plants.

a) Flowering plants are the plants which possess distinct roots, stems, flowers and fruits. e.g. Mango, Papaya, Guava.
b) Non-flowering plants are the plants which do not have distinct roots, stem, leaves, flowers or fruits. e.g. Fern, Moss.
3) Depending on the way they obtain food, plants are classified into autotrophs and heterotrophs.
a) Autotrophs are the plants which make their own food by the process of photosynthesis by using raw materials like carbon dioxide and water. e.g. Most of the green plants.
b)Heterotrophs are the plants which depend on other organisms for their food. e.g. Insectivorous plants.