Modification of Adventitous root

Modification of adventitious root 

When  roots arise from the other parts of plants like stem and leaves called adventitous root systems. Some modifications of this root are as follows -

In plants of Datepalms, the adventitious roots become hard, pointed and thorn-like. These are called root thorns .                   

In Sweet potato, Adventitious roots  help in vegetative propagation by developing buds. These buds are detached from the parent plant and   give rise to new plants after the germination.   

The parasitic plants like Cuscuta  cannot prepare their own food as they lack chlorophyll. They have to depend on host plants for nutrients .These plants develop microscopic sucking roots called haustoria that penetrate into the tissues of host plants to derive nutrition.These roots are called Sucking Roots or Parasitic Roots.            

In plants such as Bamboo and Banyan, there are  various roots hanging downwards from the branches. They provide extra support  and achorage to the stem of the tree. They penetrate the soil giving support to the horizontally spreading branches of the tree. The roots are long, woody and appear as pillars or columns. That is why they are also known as columnar roots. These roots also have lenticels for breathing. 

In some plants like Maize and Sugarcane, some  extra supporting roots arise from the lower nodes of the main stem. These roots grow towards the soil  and enter the soil. They help to keep the plant upright by providing extra anchorage.They have multiple root caps..                                           

In Some  plant like Black pepper and Money plant, roots are found in stem  such as climbers. They arise from the nodes and internodes. These  stems of the climbers run upside and provide the support. 

In Vanilla single tendril-like roots arise at the nodes. These are called tendrillarroots.                         

Clinging Roots are also modifications of adventitious roots. They are found in epiphytes likeorchids.                                        

Some roots are found in tropical forests that are nutrient deficient and  prevent the tree from falling over  and also absorb more nutrients. These roots are termed as  Buttressroot.                                    

In aquatic plants like water hyacinth , roots are spongy and have  air filled cavity.These   roots are present at nodes. These roots contain air filled tissue called aerenchyma. The roots are called floating roots. These roots maintain buoyancy to the plant for floating. They store water and help in the floating of plants. They also help in the exchange of gasses.                                 

Some adventitious roots found at the base of underground stems. These roots are swollen and keep the aerial shoots under the soil. These roots are called pull roots as in  Allium.