An assessment of suprageneric phylogeny in Cyperaceae using rbcL DNA sequences

The phylogeny of suprageneric groups in Cyperaceae has been examined by cladistic analysis of rbcL sequence data of 80 species in 40 genera. The results support the family as monophyletic and derived from a juncaceous grade. Oxychloe (Juncaceae) has moderate support as the sister taxon to Cyperaceae. Several monophyletic groups correspond to previously recognised tribes, and some similarities are noted between this analysis and previous cladistic analyses of primarily morphological data. Support is also given for the removal of Hellmuthia from tribe Hypolytreae, the transfer of Isolepis nodosa to Ficinia, and the inclusion of Oxycaryum and Kyllingiella in tribe Cypereae. A polytomy comprising Cyperus, Juncellus, Kyllinga and Pycreus indicates a broader circumscription of Cyperus. The greatest uncertainty lies with the generic and tribal status of the Scirpeae.