The carnivorous angiosperm family Lentibulariaceae comprises about 280 species in 3 genera (Utricularia, Pinguicula, Genlisea) and is of nearly worldwide distribution. It belongs to the order Lamiales within euasterids. From representatives of Lentibulariaceae and different outgroup taxa of the Lamiales the whole trnK intron including the matK gene was sequenced. The size of the matK coding region in Lentibulariaceae ranges between 1521 and 1581 bp. Size differences are caused by indels from 3 - 36 bp, which accumulate in the first half of the gene. The length of the noncoding region adjacent to the 5´ end of matK is 729 - 780 bp, and of the region adjacent to the 3´ end 305 - 330 bp. Sequence variability within Lentibulariaceae is 23% for the coding region as compared to 27% for the noncoding region. For the large 5´ noncoding region a robust alignment was obtained, whereas the short 3´ region could not be aligned all over due to high numbers of indels. Parsimony analyses based on substitutions and carried out independently for the matK gene and the long 5´noncoding region yielded identical, well resolved phylogenies with high bootstrap and decay support. The matK indels appear to be highly informative phylogenetically and seem to be much less homoplastic than substitutions. Lentibulariaceae appear monophyletic and Byblis is resolved as closest relative. Within Lentibulariaceae, Pinguicula diverges first and its species appear as a terminal clade on a long branch. Genlisea is sister to Utricularia with quite similar branch-lengths within the topology of the Genlisea-Utricularia-clade.

Key words: carnivorous plants, Lentibulariaceae, matK, molecular systematics, trnK intron