RT Journal Article SR Electronic(1) A1 Normand, Philippe A1 Nguyen, Thanh Van A1 Battenberg, Kai A1 Berry, Alison M. A1 Heuvel, Brian Vanden A1 Fernandez, Maria P. A1 Pawlowski, KatharinaYR 2017 T1 Proposal of 'Candidatus Frankia californiensis', the uncultured symbiont in nitrogen-fixing root nodules of a phylogenetically broad group of hosts endemic to western North America JF International Journal of Systematic and Evolutionary Microbiology, VO 67 IS 10 SP 3706 OP 3715 DO https://doi.org/10.1099/ijsem.0.002147 PB Microbiology Society, SN 1466-5034, AB The genus Frankia comprises a group of nitrogen-fixing actinobacteria that form root-nodule symbioses with perennial dicotyledonous plants in the nitrogen-fixing clade. These bacteria have been characterized phylogenetically and grouped into four clusters (clusters 1–4). Cluster 2 contains mostly uncultured strains that induce nodules on species of the genera Datisca (Datiscaceae), Coriaria (Coriariaceae), Ceanothus (Rhamnaceae) and several genera in the family Rosaceae (Cercocarpus, Chamaebatia, Dryas, Purshia), all of which except members of the genus Coriaria are present within the California Floristic Province (CFP) or neighbouring areas of western North America. Those strains occurring in western North America are genetically very closely related to one another, and genetically distinct from strains characterized from other locales. We hereby propose to create a 'Candidatus Frankia californiensis' species for those cluster 2 strains of the genus Frankia with both high genetic similarity and a geographical distribution in or near the CFP., UL https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/ijsem.0.002147