This data set includes data from recordings of 5883 individual flowers of the perennial herb Lathyrus vernus belonging to 558 flowering events (i.e. one plant individual flowering in one year) over three years (1987-1989). It includes data on phenology, reproductive succress and seed predation of individual flowers, as well as data on the position of the flower within the raceme, and of the raceme within the plant. The data wree collected in a population of L. vernus located in a deciduous forest in southeast Sweden (58.9496 N, 17.6097 E).