1. Form, function modification in plant
Modification of roots Some roots perform special functions. As such, their form and structure differs from those of normal roots. Modified roots may be underground or aerial.

2. Underground root modifications
Taproot and adventitious roots are modified to perform functions of storage and vegetative propagation.

3. Taproot modifications (for storage)
Tap roots may store food reserves for which they become swollen and assume various shapes.
Four types identified:
Fusiform root - Modified tap root is thickened in the middle and tapers towards both ends (e.g., Raphanus sativus - the Radish)
Napiform root - Modified tap root is greatly swollen at base, but abruptly narrows into a tail-like portion. (e.g. Beta vulgaris - Beetroot)
Conical root - Broad at the base and gradually tapering towards the apex (e.g. Daucas carota - carrot)

4. Adventitious root modifications
Tuberous root (e.g. Ipomoea batatas - Sweet potato) . Modified adventitious root swollen without any definite shape Fasciculated roots (e.g. Asparagus, Dahlia) A number of adventitious roots arise as a cluster from almost the same level at the base of the stem. Nodulose roots (e.g. Curcuma amada - mango ginger) . Root becomes swollen at its tip. Moniliform roots (e.g. Momordica) Roots show beadlike swellings at frequent intervals. Annulated roots (e.g., Ipecac) Adventitious roots have a series of ring-like swellings on their surface.

6. Zea mays
Adventitious roots arise from anything other than the radicle

7. Aerial root modifications
Aerial roots are adventitious roots which develop from aerial parts of the plant to perform various functions.
a). Mechanical Support
Prop roots (e.g. Ficus benghalensis)
Adventitious roots arise from horizontal branches and grow vertically downwards. They function as pillars (columnar roots), giving mechanical support to the branches.
Stilt roots (e.g. Pandanus)
Adventitious roots arise from lower part of main stem and grow obliquely towards the soil. They keep the plant erect by giving additional support.
Climbing roots (e.g. Piper betel – Pothos)
Roots arise from nodes and help in attaching the climbing stem firmly to a support like a tree or a wall, by various mechanisms.

8. Haustoria or sucking roots (e. g
Haustoria or sucking roots (e.g. Cuscuta ) Root penetrates into tissue of host plant and draw nutrients from the host. Such parasitic plants are not completely photosynthetic. Pneumtophores or respiratory roots (e.g. Avicennia, Rhizophora) Plants growing in marshy ,water-logged soils which contain almost no air, develop some branches which grow vertically upwards into the air. Such roots are provided towards the upper end with numerous pores through which gases diffuse in and out.

9. Floating roots (e.g. Jussiea) In Jussiea, special, spongy, adventitious roots (floating or respiratory roots) enclose aerenchyma tissue. These roots usually develop above the level of water and serve to store up air and help in buoyancy of the plant. In addition, floating roots may be respiratory. Epiphytic roots (Vanda) Epiphytes grow on other plants, and have special adventitious roots, the outer region of which is made up of velamen tissue. This tissue absorbs moisture from the air and makes it available to the plant.

10. Summary of root modifications