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TitleRoot System
TagsPlants Horticulture And Gardening Root Branches Of Botany Plant Morphology
File Size374.1 KB
Total Pages7
Table of Contents
                            Modifications of Roots
	Underground Root Modifications
	Tap Root Modifications (for storage of food)
	Adventitious Root Modifications
	Aerial Root Modifications
	A. For Mechanical Support
	B. For Vital Functions
	Summary of Root Modifications
Document Text Contents
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• Stilt roots e.g. Pandanus : In Pandanus the adventitious roots arise from the lower part of the
main stem and grow obliquely towards the soil. They serve to keep the plant erect by giving
additional support.

• Climbing roots or clinging roots e.g., Piper betel, Pothos, etc : These roots arise from the
nodes and help in attaching the climbing stem firmly to a support like a tree or a wall, by
various mechanisms.

B. For Vital Functions
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• Haustoria or sucking roots e.g. Cuscuta : Parasites like Cuscuta develop a kind of root which
penetrates into the tissue of the host plant and help to draw nutrients from the host by sucking
it. The parasitic plants are not completely equipped to prepare their food. Hence, such plants
have to depend on host plants for nutrients.

fig. 27.8 - Modified Adventitious Roots: Cuscuta
(For vital functions)

• Respiratory roots or breathing roots or pneumtophores.
e.g., Avicennia, Rhizophora.

fig. 27.9: Pneumatophores
A number of plants growing in marshy water-logged soils which contain almost no air, develop some
branches which grow vertically upwards into the air. These roots are called breathing roots or
pneumatophores. Each such root is provided towards the upper end with numerous pores through
which gases diffuse in and out.

• Floating roots e.g., Jussiea: In Jussiea which is an aquatic plant, special spongy roots called
floating or respiratory roots arise from the plant. They are adventitious and enclose a tissue
called aerenchyma. These roots usually develop above the level of water and serve to store up
air and help in buoyancy of the plant. In addition, the floating roots may also perform the
respiratory function. Hence, they are also called respiratory roots.

• Epiphytic roots e.g., Vanda: In epiphytes like orchids which grow on other plants, special
adventitious roots called epiphytic roots are produced. The outer region of the root is made up
of a special tissue called the velamen. This tissue absorbs moisture from the air and makes it
available to the plant. These roots do not penetrate the host tissue like parasitic roots.

Summary of Root Modifications
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