Sequence analyses of five plastid DNA regions (part of the matKexon, the trnLintron, the trnL-Fintergenic spacer, and the rpl12and rps16introns, totalling more than 3700 characters in the aligned matrix) were used to investigate the monophyly of Tulipaand its relationships with other genera of Liliaceae. If the genus Amanais recognised for T. edulisand allies, the remainder of Tulipais strongly supported as monophyletic. Amanaand Erythroniumare the closest relatives of Tulipas.s. In Tulipa, two major clades, more or less corresponding to Tulipasections Tulipa(Leiostemones) and Eriostemonesas recognised by Hall (1940), are strongly supported, but resolution within these clades is poor, due to low levels of sequence divergence. Tulipa sprengeri, treated as an isolated species by Hall, is shown to be a member of section Eriostemones, and at least some members of subsection Clusianae, section Tulipa, fall in an isolated position closer to T. uniflora(thought by Hall to be a member of Tulipasection Orithyia) than to members of section Tulipa. These results will be discussed in terms of the morphology and ability of the different taxa to hybridize with each other.

Key words: Amana, Erythronium, Liliaceae, molecular phylogenetics, Tulipa