Advancing Archaeobotanical Methods: Morphometry, Bayesian Analysis and AMS Dating of Rose Prickles from Monteagudo Almunia, Spain (12th Century-Present).

BACKGROUND: While archaeological evidence is crucial for understanding the origins of ancient rose varieties in Western Europe, the botanical composition of medieval Islamic gardens remains largely unknown. This study focuses on the rose cultivation at the 12th-century Almunia del Castillejo de Monteagudo in Murcia, Spain, a key Islamic site in al-Andalus. METHODS: Morphometric analysis and Bayesian hypothesis testing were applied to characterize rose prickle remains recovered from the site. The prickles were found in stratigraphic contexts above the original garden and yielded post-medieval radiocarbon dates (18th-19th centuries AD). The morphological parameters of the archaeological specimens were statistically compared against reference collections of known rose species to determine their probable botanical origins. RESULTS: The analysis identified two distinct prickle morphotypes. Statistical comparisons indicate these correspond to the white musk rose (Rosa moschata Herrm.) and to yellow roses from the Rosa foetida Herrm. complex (including R. lutea Mill. var. persiana Lem.). Both species are historic introductions from West Asia. The morphometric parameters demonstrated significant diagnostic value for the species-level identification of archaeological rose remains. CONCLUSION: Despite the post-medieval date of the prickles, the presence of R. moschata and R. foetida suggests the continuity of cultivation for rose species originally already known during the medieval Islamic period. This provides direct archaeological evidence for the role of al-Andalus gardens in the dissemination of West Asian rose diversity, highlighting the lasting impact of medieval Islamic horticulture on the Iberian Peninsula.