show Abstracthide AbstractMedicago polymorpha is an annual medic native to regions surrounding the Mediterranean. It is thought to have been introduced to CA during the mid to late 1800's and is now considered invasive as it outcompetes many native plants. In order for M. polymorpha to have become established in CA, it also required the coinvasion of its symbiotic nitrogen-fixing bacteria Ensifer medicae. Little is currently known about symbiotic coinvasion or population dynamics of invasive soil bacteria, so this system provides a good opportunity to study the evolutionary forces involved. Here, we sequenced and assembled genomes of 17 strains of E. medicae isolated from M. polymorpha root nodules in the McLaughlin Reserve in CA.