Plant adaptation to diverse conditions includes species divergence in photosynthetic physiology. This dataset contains photosynthetic light response curve data collected on a single germplasm accession for each of 28 diverse wild sunflower species (genus Helianthus) grown under controlled greenhouse conditions. Gas exchange data was collected using a TARGAS-1 portable photosynthesis system, with standard outputs for this instrument provided at each data point collected across nine light levels from complete darkness to 2500 micromoles per meter squared per second of photosynthetically active radiation flux.

The dataset includes directly measured values (reference and analysis values for carbon dioxide and water vapor, atmospheric pressure and flow rate, exterior and interior light levels, and cuvette temperature), as well as calculated values (leaf temperature, transpiration rate, vapor pressure deficit, stomatal conductance, net photosynthetic assimilation, and intercellular carbon dioxide concentration). Note that four species with narrow leaves did not fill the chamber cuvette (see article for adjustment method), and 3% of data points have partially missing data values due to the instrument entering auto-zero cycle.

The dataset was used to conduct function-valued trait (FVT) modeling of the evolution of light curves with phylogenetic comparative methods. The dataset could be used as part of meta-analysis or synthesis requiring light response curve data, with appropriate considerations of data limitations.