From the Andes a number of small Scirpus species are known which all look very similar. They are characterized by one terminal spikelet or a group of closely clustered spikelets. Because clear diagnostic features are missing the species were put into the heterogeneous genus Scirpus sensu latissimo. However, none of these species belongs to the genus Scirpus s.s., as now circumscribed. To reveal the natural relationships of the species a morphological, anatomical and molecular analysis was performed. The Andean scirpoids can be arranged into several genera including Oreobolopsis, Trichophorum, Phylloscirpus, Amphiscirpus and a new genus Zameioscirpus. Within the genus Oreobolopsis the presence of a second species became evident. To understand their phylogenetic relationships within the tribe Scirpeae rbcL and trnL-F sequence data were obtained and inserted into an existing datamatrix which was analysed using the parsimony algorithm of PAUP (heuristic tree search). The Andean scirpoids form a major clade with Scirpus s.s., Blysmus and Eriophorum. A branch and bound tree search was carried out on this smaller group. The DNA data support the presence of the new genus Zameioscirpus. Scirpus boliviensis should be recombined into Phylloscirpus and Trichophorum and Oreobolopsis are very closely related. The position of Amphiscirpus remains unresolved.