Morphometric and aDNA study of charred plant remains found in the Monteverdi medieval castle, Civitella Paganico, Grosseto, Italy

Abstract

The castle of Monteverdi is a medieval settlement in central Italy, located on a hill that once controlled the communication routes between the Tyrrhenian coast and Mount Amiata. The remains of the castle’s walls cover the flat summit of a large ovoid ridge, enclosing a series of structures. The excavation focused on one of these areas, which was characterized by the presence of a small oven, revealing numerous charred carpological and xylological remains dating from the mid to late 12th century. These were subject of a multidisciplinary study, which included morphological, morphometric and genetic investigations, with the aim of obtaining information about human-environment interactions, particularly in relation to the exploited cereal grains. Traditional archaeobotanical analyses allowed us to identify a range of plants available at the site, such as cereals (mostly barley and naked wheats), pulses and weeds (represented by Lolium temulentum). Woody taxa correspond to the typical vegetation of Maremma (Tuscany, Grosseto, Italy). Subsequently, through geometric morphometry, the profiles of a selection of ancient and modern cereal of Triticum caryopses were extracted, and their average shapes were analyzed by comparing Euclidean and genetic distances. This allowed for the assessment of homologies and differences with some current cultivars of the same species. Finally, molecular analyses successfully applied to charred material made it possible to identify grains of Triticum aestivum/durum with genetic characteristics comparable to some accessions still cultivated in Italy today.