Page 99 - Pharmacognosy-II (06-PG 303)
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Roots
• The root is the portion of the plant axis which grows vertically downwards
into the soil, away from light, it never develops leaves, usually bearing no buds. It
does not show nodes and internodes and is characterized by the absence of
chlorophyll. The root bears branches, which are similar in structure and in general
characters to the main root.
• The branching of the root is usually lateral and the lateral branches are thinner and
less strong than the parent root.
Types of roots:
1 – Primary roots: Developing into tap-root as in Senega .
2 – Secondary roots: or lateral roots as in Krameria.
3 – Adventitious roots: They usually arise from the stem as in Ipecacunha.
4 – Fibrous roots: Very slender roots as in grasses.
5 – Root tubers, tuberous roots, (Storage roots) : they occur when the roots of any of the
previously mentioned types becomes swollen with reserve food materials. Those which
are very swollen e.g Jalap, aconite and carrot are called root tubers or tuberous or
tuberculated roots.
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