Types of roots

           
 


The root is the organ of a plant that typically lies below the surface of the soil. However, roots can also be aerial or aerating that is growing up above the ground or especially above water.

The first root that comes from a plant is called the radicle.

The four major functions of roots are

  1. Absorption of water and inorganic nutrients and transfer it to the other parts of the plant.
  2. The roots hold the plant firmly, anchoring of the plant body to the ground, and supporting it.
  3. Storage of food and nutrients like carrots and radish, root store food for the plants.
  4. Vegetative reproduction
 
Different types of root
  • Tap roots
  • Fibrous root
  • Aerial roots
  • Storage root
 


Tap Roots :

A taproot is an enlarged, somewhat straight to tapering plant root that grows downward. It forms a center from which other roots sprout laterally.

Plants with taproots are difficult to transplant.

Taproots develop from the radicle of a seed, forming the primary root. It branches off to secondary roots, which in turn branch to form tertiary roots. These may further branch to form rootlets. 

Some plants with taproots:
  • Beets
  • Burdock
  • Carrot
  • Dandelion
  • Parsley
  • Parsnip
  • Poppy mallow
  • Radish
  • Sagebrush
  • Turnip



tap root
 

Fibrous root :

A fibrous root system is the opposite of a taproot system. It is usually formed by thin, moderately branching roots growing from the stem.

For most plants species the radicle dies some time after seed germination, causing the development of a fibrous root system, which lacks a main downward-growing root.

Most trees begin life with a taproot, but after one to a few years change to a wide-spreading fibrous root system with mainly horizontal surface roots and only a few vertical, deep anchoring roots.

These roots are adventitious which means they can grow from plant organs other than roots e.g. stems.

A few plants with fibrous root systems:
  • Coconut palm
  • Banana
  • Grass
  • Onion


 

Aerial roots :

Aerial roots are short roots above the ground. They are almost always adventitious.

Types of Aerial roots

Aerial roots as supports : Non-parasitic ivy are vines that use their aerial roots to cling to host plants, rocks, or houses.

Stranglers: The Banyan tree is an example of a strangler fig that begins life as an epiphyte in the crown of another tree. Its roots grow down and around the stem of the host, their growth accelerating once the ground has been reached.

Pneumatophores : These specialized aerial roots enable plants to breathe air in habitats that have waterlogged soil. The roots may grow down from the stem, or up from typical roots.

Haustorial roots : These roots are found in parasitic plants, where aerial roots become cemented to the host plant via a sticky attachment disc before intruding into the tissues of the host. Mistletoe is a good example of this.

Propagative roots : Adventitious roots usually develop from plantlet nodes formed via horizontal, aboveground stems, termed stolons, e.g. strawberry runners and spider plant.

aerial rool
 

Storage roots :

Storage roots are those roots which store a portion of the energy/nutrients gathered or produced by a plant, potatoes , beets , ginger are some examples of them.

Many biennials - plants that live for two years, spend their first year collecting carbohydrate in their storage roots, then the second year they use their stored carbohydrate to grow fast.

storage root