XVI International Botanical Congess

The internal transcribed spacer (ITS) region of nuclear ribosomal DNA was sequenced from 216 samples representing 202 species of Allium, two species of Nothoscordum and one species of Milula. Within Allium representatives of all sections and subgenera were included. The phylogenetic analysis shows that subgenera Rhizirideum and Allium, as well as sections Reticulato-Bulbosa and Oreiprason (subgenus Rhizirideum) are polyphyletic. Most other sections of the genus are monophyletic units. Milula, a monotypic Himalayan genus, clearly groups within Allium. The ITS data support the monophyly of New World (x=7) and Old World species (x=7, 8, 9, 10) of the genus, and provide evidence for an Old World origin of Allium.