Allium lesbiacum, a new species of A. sect. Codonoprasum (Amaryllidaceae) from Lesvos Island (East Aegean Islands), Greece

Allium lesbiacum (A. sect. Codonoprasum) is described and illustrated as a new endemic species of Lesvos Island (East Aegean Islands, Greece), based on a combination of morphological, cytogenetic and molecular evidence. While it morphologically resembles species traditionally assigned to the A. paniculatum complex, as well as of the Greek endemic A. euboicum, owing to shared traits such as the occurrence of a unilateral spathe valve, nrITS phylogenetic analyses clearly exclude A. lesbiacum from these lineages. Instead, the species forms a well-supported sister clade to the Balkan polyploid A. nebulosum, together constituting a lineage sister to the A. flavum complex. Cytogenetic data further support species delimitation because A. lesbiacum has diploid and triploid chromosome complements and is characterized by unusually small chromosomes and the lowest absolute genome sizes recorded among diploid and triploid representatives of A. sect. Codonoprasum. These findings emphasize both the distinct evolutionary position of A. lesbiacum and the prevalence of morphological convergence within the section. Citation: Nikolopoulos I., Bareka P., Adamakis I.-D. S., Kobrlová L., Duchoslav M. & Trigas P. 2026: Allium lesbiacum, a new species of A. sect. Codonoprasum (Amaryllidaceae) from Lesvos Island (East Aegean Islands), Greece. – Willdenowia 56: 373–387 Version of record first published online on 21 July 2026.