Taxonomic reassessment of Myrtus communis subsp. baetica: A species of Andalusi heritage value

Myrtus communis L., is a Mediterranean evergreen shrub represented in the Iberian Peninsula by three subspecies: subsp. communis (native), subsp. tarentina and subsp. baetica (cultivated). M. communis subsp. baetica is represented by old specimens, more more than 400 years old, which could be considered naturalized. This study integrates morphometric and statistical analyses to clarify the taxonomic status of M. communis subsp. baetica, a rare taxon of considerable botanical and cultural significance. We analyzed 28 herbariium specimens from the GDA and MGC collections. Key taxonomic morphometric traits: leaf length (LL), width (LW), area (LA), internode length (IL) and floral pedicel length (PL) were measured. Allometric correlations were evaluated, and one way ANOVA followed by Tukey´s HDS test was used to determine significant differences (p <0,01) among the studied subspecies. Results show that subsp. baetica possesses significantly larger leaves (LA= 333,3 +- 76,2 mm2, LL=56,7 +- 7,8 mm2, LW= 21, 3 +- 3,6 mm2) , a distinct LL-LA allometric relationship, and shorter internodes and floral pedicels compared with subsp. communis and subsp. tarentina. Statistical analyses confirm that these differences are robust and taxonomically meaningful. Combined with prior genetic evidence, our findings support raising subsp. baetica to species rank (Myrtus baetica (L.) Mill.) . Beyond its taxonomic distinctiveness , this species represents a living botanical legacy of Al-ándalus, encompassing centuries-old cultivated specimens mainly from Granada and Almería. Recognizing its species status is crucial for conservation, safeguarding its genetic heritage and historical-cultural value.