This data publication provides data from burning experiments performed at the Department of Physical Geography, Goethe Univeristy, Frankfurt am Main (Germany). We burned plant specimens from seven graminoid, fifteen forb, and one shrub species from the steppe area in the Dobrogea, Black Sea, Romania, and Konoplyanka, Trans-Urals, Russia. The experiments were conducted to determine the effect of increasing temperatures on the charcoal mass, morphometric characteristics, and morphologies of charred plant material. For this we dried these plants in a desiccator (40°C) for 24 h. Subsequently, following the protocol of Feurdean (2021), we roasted the plant material in a muffle furnace at five district temperature settings: 250, 300, 350, 400, and 450°C. For each temperature subset, remains of individual plant species from the entire plant or as selected plant parts (Table 1), were placed in ceramic crucibles, weighed, then placed into the cold muffle oven covered with a lid to limit oxygen availability and avoid mixing the charred particles. The temperature was gradually raised for one hour, after which it was held constant for a duration of two hours. Crucibles with charred plants were cooled in a desiccator, then weighed to calculate the charred to pre-burning mass ratio. A small part of the charred mass was gently disaggregated with a mortar and pestle to mimic the natural breakage that charcoal particles experience over time through sedimentation processes. The charred and disaggregated sample was then washed through a 125 μm sieve to remove smaller fragments. Photographs of charcoal particles were manually taken at 4X magnification with a digital camera (KERN ODC 241 tablet camera. The charcoal particles and morphometric measurements, including the major (L) and minor (W) axes surface area (A), and perimeter (P) for individual charred particles larger than 150 μm, were automatically determined from these photographs using the algorithm of Feurdean (2021). Subsequently, we calculated the aspect (L/W; W/L) and A/P ratios). These metrics were applied on more than 150 charcoal particles (range between 41 and 508), per sample; the lower number of measurements generally corresponds to samples burnt at high temperatures, where particles were more susceptible to breakage or partial ashing.