Genetic polymorphism in Lactuca aculeata populations and occurrence of natural putative hybrids between L. aculeata and L. serriola

► We studied twenty-eight L. aculeata accessions, and three putative hybrids L. aculeata × L. serriola. ► There was low morphological variability of L. aculeata. ► Eight enzymatic systems were analysed for their polymorphism. ► A highly homogeneous group of the 28 (ca 75%) L. aculeata accessions were detected. ► Three accessions are considered natural putative hybrids L. aculeata and L. serriola.