Phylogenetic relationships within the genus Cladonia, including Cladina (Cladoniaceae, Lecanoromycetes), were reconstructed based upon simultaneous analyses of DNA sequences and morphological and chemical data. We used sequences from the internal transcribed spacer 1 (ITS1), the 5.8 rDNA gene, and the internal transcribed spacer 2 (ITS2) of the nuclear rDNA gene cluster, and partial sequences from the protein-coding beta-tubulin gene. The analyses included 235 specimens of 168 taxa representing all currently recognized sections of Cladonia and Cladina and the outgroup genera Cladia, Pycnothelia, and Rainalea. Analyses were performed using optimization alignment with three different parameter values. The results of all analyses support the inclusion of Cladina in Cladonia. The current sectional division of Cladonia was not supported, and a new provisional classification for the genus is proposed.