Frankia
![](/Images/godic/202501/14/An_alder_root_nodule_gall4219.JPG")
![A section through an alder root nodule](/Images/godic/202501/14/A_sectioned_alder_root_nodule_gall4219.JPG")
Frankia is a genus of nitrogen fixing, filamentous bacteria that live in symbiosis with actinorhizal plants, similar to the Rhizobia bacteria that are found in the root nodules of legumes in the Fabaceae family. Bacteria of this genus also form root nodules.