Allium paniculatum L. is commonly recorded from the Euro-Mediterranean and Irano-Turanian regions. Evidence from literature and herbarium collections revealed that many different taxa of A. sect. Codonoprasum Rchb., all characterized by big size, diffuse and densely flowered umbrella, very long spathe valves, long pedicels, and cylindrical-campanulate perigon, have been wrongly attributed to this species thus affecting records on its geographic distribution and morphological characterization. In order to define the true identity of A. paniculatum, we analyzed specimens coming from the type locality (Don River), and provided details on morphology, ecology, karyology, leaf anatomy, seed morphology and seed coat micro-sculpturing. Taxonomic and phylogenetic relationships with related species of sect. Codonoprasum and with other taxa of different sections were investigated by means of morphological characters and molecular data from the internal transcribed spacers (ITS) nrDNA and the trnH-psbA cpDNA region. Maximum parsimony and Bayesian inference analyses of molecular data recovered two main clades in A. sect. Codonoprasum and clearly separated A. paniculatum from related taxa. The taxonomic implications of these patterns of relationships are discussed. To our knowledge, this is the first study documenting in-depth phylogenetic relationships within A. sect. Codonoprasum.Key words: Allium paniculatum, A. sect. Codonoprasum, karyology, morphology, phylogeny, seed coat sculpturing, taxonomy.For a long time Allium paniculatum L. has been regarded as a remarkably variable species, counting a wide range of morphologically different forms. More than thirty taxa, at specific or lower rank, were included into the A. paniculatum complex, many of which have been gradually recognized as species. The most relevant diacritic characters of this group mainly regard gross size, length of spathes, shape of inflorescence, shape and morphology of some floral traits (Levan, 1937;Wilde-Duyfjes, 1976;Stearn, 1980). Describing A. paniculatum, Linnaeus (1759, pp. 978) just provided this short protologue: "A. caule subteretifolio umbellifero, pedunc. capillaribus effusis, stamin. subulatis, spatha longissima", which was also quoted in Linnaeus (1762, pp. 428). These few diagnostic characters often caused erroneous attributions of specimens and, based on literature and herbarium surveys, several taxa of A. sect. Codonoprasum Rchb., which usually exhibit big size, many-flowered and spread inflorescences, long pedicels, very long spathe valves, and cylindrical-campanulate perigon, have been improperly referred to A. paniculatum. As a matter of fact, the name A. paniculatum has been mistakenly applied to samples of A. dentiferum Webb & Berthel., A. fuscum Waldst. & Kit., A. oleraceum L., A. pallens L., A. tenuiflorum Ten., etc. (Brullo et al., 1991(Brullo et al., , 1996(Brullo et al., , 2001(Brullo et al., , 2003(Brullo et al., , 2008a).Due to these frequent misleading interpretations, main floras and taxonomic revisions on the genus...