Integrative taxonomy reveals two new species of Gagea (Liliaceae) from the Pamir–Alay Mountains, Central Asia

The genus Gagea (Liliaceae) is a taxonomically complex and species-rich group widely distributed in the Irano–Turanian region, with Central Asia recognized as one of its primary centers of diversity. In this study, we describe two new species, Gagea furkatii Levichev, Turginov & Kurbaniyazova, sp. nov. and Gagea quasibergii Turginov, Levichev & Kurbaniyazova, sp. nov., from southern and central Uzbekistan and southern Tajikistan, based on an integrative approach combining morphological and molecular evidence. Morphological examination of herbarium and field-collected specimens revealed a unique combination of diagnostic characters that clearly distinguish both taxa from closely related species. Phylogenetic analyses based on nuclear ribosomal ITS sequences were performed using the Maximum Likelihood (ML) method. The results demonstrate clear genetic differentiation of both species, supported by high bootstrap values (BS = 99), and distinct clustering patterns in ordination analyses. Pairwise genetic similarity ranged from 81.7% to 100%, indicating both intra- and interspecific divergence. Divergence time estimation suggests that speciation occurred during the Early Pleistocene (~1.8–2.0 Mya), likely driven by climatic fluctuations and geographic isolation. The combined molecular and morphological evidence supports the recognition of G. furkatii and G. quasibergii as independent evolutionary lineages. These findings highlight the Pamir–Alay region as an important center of recent diversification and emphasize the value of integrative taxonomy in resolving species boundaries within Gagea.