Actinorhizae    - Actinorhizae are organs composed of root tissue and actinomycetes.  The actinorhizae fix nitrogen, which means that nitrogen in the air is converted to a form that can be used by the plant.  In other words, the actinorhizae fix atmospheric pure nitrogen to ammonia, which can be chemically altered by some bacteria to nitrate ions.  Actinorhizae are common on trees in many genera, Alnus, Elaeagnus, Casuarina, to name a few.  The actinomycetes are microorganisms that have some characteristics of fungi and bacteria.  Actinomycetes give soil that "good earth smell".   Bacterial nodules are common on many plants in the legume family.  Nitrogen is fixed by bacteria in the nodules.  Note: Mycorrhizae are organs that facilitate absorption of water and elements.  Mycorrhizae do not fix nitrogen.

1) Actinorhizae  2)  non-woody root of Alder (SHIGO 2002)

Soil Connections!







 Actinorhizae on SWEETFERN COMPTONIA (SHIGO 2002)










Dictionary MAIN PAGE
Text & Graphics Copyright © 2007 Keslick & Son Modern Arboriculture
Please report web site problems, comments and words of interest, not found.