Spring temperature drives phenotypic selection on plasticity of flowering time

Data on field observations of flowering time and fitness of the perennial forest herb <em>Lathyrus vernus</em> and on spring temperature from weather station data. The dataset includes 22 years of data (1987–1996 and 2006–2017) from a <em>L. vernus</em> population located in a deciduous forest in Tullgarn, SE Sweden (58.9496 N, 17.6097 E). It includes records from 837 individuals (607 from 1987 to 1996, and 230 from 2006 to 2017), and from 2478 flowering events. The dataset includes the following variables: year: year of the recording id_nr: numeric plant id id: unique plant id (combination of numeric plant id and period) fcode: flowering code (1 if the plant flowered on that year, 0 if not) FFD: First Flowering Date n_fl: number of flowers n_fr: number of fruits totseed: total number of seeds intactseed: total number of intact seeds (not damaged by seed predator beetles) shoot_vol: shoot volume period: old (1987–1996) or new (2006–2017) n_years_fl_fitness: number of years when data on flowering and fitness is available n_years_study: number of years when the plant was included in the study mean_4: Average daily mean temperature of April (calculated from nearby meteorological station data) cmean_4: Mean-centred average daily mean temperature of April