Nodules harbour microbial communities composed of rhizobia and other lower-abundance bacteria. These non-rhizobial bacteria can promote plant growth. However, their genomic diversity and how this relates to their plant growth-promoting traits remain poorly investigated. Here, we isolated 14 Pseudomonas strains from the nodules of Lotus plants, sequenced their genomes, analysed their genomic and phylogenetic diversity, and assessed their ability to promote plant growth. We identified five distinct species, including a novel species named Pseudomonas monachiensis sp. nov., with strain PLb12A