The species from Cladonia section Unciales are characterized by the absence of squamules and soredia on the corticate podetia and the presence of usnic acid. Different subspecies, varieties and forms have been distinguished in the type species C. uncialis. In this study, a molecular phylogeny of Cladonia uncialis and members of the traditionally recognized section Unciales, along with additional potentially allied species, was constructed. DNA sequences from three gene loci, namely ITS rDNA, IGS rDNA and ß-tubulin, were analyzed using Maximum Parsimony, Maximum Likelihood, and Bayesian methods. Eleven species were analyzed for the first time using DNA sequence data. Cladonia uncialis subsp. uncialis and subsp. biuncialis were recognized as distinct taxa. The recognition of C. pseudostellata as a species was not supported by the analyses, but it represents a hypothamnolic acid chemotype, which is reported here as new to Europe (Scotland). The presence of subsp. biuncialis in North America (Newfoundland) was substantiated. The subsp. uncialis usually lacks squamatic acid, but in the eastern United States a morph referred to as subsp. uncialis does normally contain that acid. However, this morph did not attain taxonomic recognition based on phylogenetic analyses. All the other taxa formerly included in sect. Unciales turned out to belong to other groups of Cladonia, mainly Amaurocraeae, Borya, Divaricatae, and Perviae. The formerly recognized genus Cladina (reindeer lichens) is non-monophyletic, consisting of three groups within Cladonia, making the concept Cladina even nomenclaturally useless. Alternative topology tests rejected the monophyly of C. pseudostellata, section Unciales and Cladina.