Difference between Normal Root and Coralloid Root in Cycas

Cycas- Normal vs Coralloid Root

Cycas is a Gymnosperm coming under the Class Cycadopsida and Order Cycadales. Cycas plants have TWO types of Roots – (1) Normal Roots and (2) Coralloid Roots. In this post, we discuss the Similarities and Differences between Normal Root and Coralloid Roots in Cycas with a Comparison Table.

Similarities between Normal Root and Coralloid Root

Ø  Anatomically both the roots are differentiated into epidermis, cortex, endodermis, pericycle and stele.

Ø  The stele in both the groups composed of radially arranged xylem and phloem.

Ø  Pith is absent or small in both the groups

Difference between Normal Root and Coralloid Root

Normal RootCoralloid Root
Morphologyroots of cycascoralloid roots of cycas
DevelopmentDevelop from the radicle of embryo.Develop from the normal roots
Tap-rootFrom the tap-root system.Do not form the tap-root.
GeotropismPositively geotropic and grow downward.Negatively geotropic and grow upward.
BranchingComparatively less branched.Coralloid roots are highly dichotomously branched.
AppearanceAppear as normal roots of plants.Appear as corals (due to severe branching).
Root HairsRoot hairs are present.Root hairs are absent.
CortexCortex is small and uniformCortex is very large and differentiated into THREE zones – outer, middle and inner zones.
Algal ZoneAlgal zone is absent in the cortex.A broad algal zone is present in the middle cortex.
SymbiosisNO symbiotic association with blue-green algae.Blue-green algae present in the algal zone of cortex shows symbiotic association with the root.
Vascular TissueVascular tissue is diarch (two strands of xylem and phloem).Vascular tissue is triarch (three strands of xylem and phloem).
Secondary ThickeningSecondary thickening occurs.Secondary thickening is usually absent.
FunctionThe main function of the normal root is absorption and anchorage.Function coralloid root is nitrogen fixation.
Anatomycycas root record diagramcoralloid root record diagram

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You might also like…

@. Gymnosperms: General Characters

@. Gymnosperms: Classification

@. Cycas – Morphology, Anatomy, Reproduction & Life Cycle

@. Economic Importance of Gymnosperms

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