sp. nov., a nitrogen-fixing lineage isolated from nodules of the caesalpinioid species and characterized by tolerance to high temperature .

The symbioses between legumes and nitrogen-fixing rhizobia make the greatest contribution to the global nitrogen input via the process of biological nitrogen fixation (BNF). stands out as the main genus nodulating basal Caesalpinioideae. We performed a polyphasic study with 11 strains isolated from root nodules of , an annual multi-functional native legume of the USA.

sp. nov., an effective nitrogen-fixing symbiont of partridge pea [ (Michx.) Greene], a native caesalpinioid legume broadly distributed in the USA.

Information about the symbionts of legumes of the Caesalpinioideae subfamily is still limited, and we performed a polyphasic approach with three strains-CNPSo 3448, CNPSo 3394 and CNPSo 3442-isolated from , a native legume broadly distributed in the USA. In the phylogenetic analysis of both the 16S rRNA gene and the intergenic transcribed spacer, the CNPSo strains were clustered within the superclade. Multilocus sequence analysis with six housekeeping genes-, , , , and -indicated that is the closest species, with 83 % of nucleotide identity.