Cycad Root Nodules

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I studied the unique symbiosis between Cycad root nodules and nitrogen-fixing Cyanobacteria. Very few terrestrial plants have symbiotic relationships with Cyanobacteria. The only flowering species to have such a symbiosis are in  the genus Gunnera. One Gunnera species grows here and might be worth some further attention.

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Coralloid Root Nodules of a Cycad

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Long Section of Coralloid Root nodule containing Cyanobacteria

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Microscopic view of the "algal zone" in a Cycad Root Nodule. The dark objects are Cyanobacterial cells.

Nostoc filaments - Free Living - Nostoc species colonize Cycad root nodules. How they get in is a mystery!!!!!!!!!