Two data files for "Does a facultative mutualism limit range expansion" by J. Stanton-Geddes and C. Anderson, published in Oecologia. 1) field_inoculation_expt_2009.csv This is the data from the field inoculation experiment that was performed at 5 sites described in the paper. Details of each column are: site - site of planting (see online supplementary material of the paper for specific locations) region - relative to the plant's current distribution soil.perN - percent nitrogen from ten pooled soil samples taken haphazardly at each site pop - seed population source (see online supplementary material of the paper for specific locations) trt - R: rhizobia inoculation N: not inoculated pos - planting location germ - 0: not germinated 1: germinated (in the paper this is referred to as early-season survival) e.leaves - number of leaves recorded approx. 4 weeks after planting when germination was recorded july.stage - growth stage at mid-season measurements. this data was not used in the paper. 0: dead, 1: vegetative, 2: flowering without seed pods, 3: plant with developing green pods, 4: plant with ripening brown pods, 5: plant senescing following reproduction july.height - height in centimeter, mid-season july.leaves - number of leaves, mid-season num.herbivory - number of leaves with visible herbivory damage, mid-season num.disease - number of leaves with visible disease, mid-season jul.browsed - 0: not browsed, 1: browsed (presumably by deer) nodules - this was only recorded for the uninoculated plants (whether they were browsed or not). 0: no nodules, 1: at least one nodule remaining columns with prefix "fall" are same as those for mid-season measurements with the addition of fall.branch - number of branch longer than 5 cm fall.pods - number of seed pods, counting the pedicel if the pod had already fallen off 2) greenhouse_inoculation_expt_2010.csv Data from the greenhouse inoculation experiment to test for differences in rhizobia quality. Most columns are self-explanatory except for: date_planted - germination rates were low and variable, so it took a number of days before we had adequate germinate seeds to begin the experiment. once a seed germinated in a petri dish, it was transplanted to a pot. the date this occurred is given in this column. branch_mar12 - branch number near the end of the experiment. this was not highly variable, so not used in the analysis flower_mar12 - whether a plant had flowers (1) or not (0) near the end of the experiment. few plants reached flowering so this data was not used