Visualizing archaeobotanical data: A comprehensive photographic record of desiccated plant remains from an early modern context at Santi Quattro Coronati, Rome

The "Santi Quattro Coronati - archaeobotanical plates" dataset presents a comprehensive photographic collection of carpological remains recovered from a pit in the complex of Santi Quattro Coronati (Rome, Italy). The deposit, dated between the late 15th and the mid-16th century, yielded a diverse assemblage of desiccated plant remains. The dataset is novel in that it provides the complete photographic documentation of all identified taxa from a single Early Modern archaeological context, a chronological phase that remains underrepresented in Italian archaeobotanical research. The photographic documentation focuses on a representative sample of each taxon identified in the archaeobotanical analysis, with particular attention to the best-preserved specimens. When multiple plant parts of the same taxon were present, all were included. The dataset also includes fragile and rarely illustrated plant parts, such as cereal rachis fragments, tunics and basal plates of onion and garlic, grapevine tendrils and legume seed coats. These are often excluded from reference atlases due to their low archaeological survivability and the consequent scarcity of well-preserved comparative specimens. High-resolution images were acquired using a Leica MC205C stereomicroscope equipped with a Leica IC80HD camera and the Leica Application Suite v.4.5.0 software. Illumination was provided by the Leica LED5000 HDI™ dome system, ensuring constant, diffuse light conditions. A column of images was captured for each specimen and processed with Helicon Focus v.7.0.1 Pro through focus stacking to obtain a single fully focused image. Depending on specimen size and complexity, between 9 and 127 photographs were used per perspective. Larger samples, unsuitable for microscopic observation, were photographed using a Canon digital camera under controlled illumination. Post-processing was performed with GIMP, applying standard tools for background cleaning and masking. Each final plate includes a scale bar for size reference. The dataset is organized alphabetically by plant family and taxon. For each taxon, one or more plates are provided, displaying specimens from one to three perspectives to represent their 3D morphology. Nomenclature follows the taxonomy used in the original publication of the assemblage and has been updated according to the most recent checklist of the Italian vascular flora. A metadata .xls file is provided to facilitate consultation, reuse, comparison and integration with other archaeobotanical datasets. This dataset offers a well-documented comparative visual reference for species/genus identification and for assessing the preservation state and morphological integrity of desiccated archaeobotanical remains. Offering detailed photographic records of New World plant taxa previously identified in this context, the study enhances accessibility and understanding of these materials through visual reference. Despite being limited to a single context, the dataset represents a best-practice in archaeobotany, encouraging other researchers to share complete photographic documentation of the carpological assemblages they study, thereby supporting open science and the gradual construction of an expanding visual reference collection. The dataset is primarily intended for archaeobotanists and environmental archaeologists working on Early Modern contexts, but it can also serve researchers investigating desiccated plant remains from other chronological periods and sites.