Affinities in C 3Cyperus lineages (Cyperaceae) revealed using molecular phylogenetic data and carbon isotope analysis

Maximum likelihood and Bayesian analyses of nrDNA (ETS1f) and plastid DNA (rpl32-trnL, trnH-psbA) sequence data are presented for 'C 3Cyperus' (Cyperaceae). The term 'C 3Cyperus' indicates all species of Cyperus s.l. that use C 3 photosynthesis linked with eucyperoid vegetative anatomy. Sampling comprises 77 specimens of 61 different taxa, representing nearly all previously recognized subdivisions of C 3Cyperus and the segregate genera Courtoisina, Kyllingiella and Oxycaryum. According to our results, the Cyperus clade is divided in six well-supported clades. The first of these clades (clade1) forms three subclades largely corresponding to Cyperus sections Haspani, Incurvi and Diffusi. Clade2 comprises the entirely New World C. section Luzuloidei sensu Denton (1978). Clade3 is a highly diverse clade including two subclades: clade3a, C. sections Pseudanosporum and Anosporum plus the segregate genera Courtoisina and Oxycaryum; and clade3b, C. section Fusci. Clade4 corresponds to C. section Alternifolii and clade5 to C. section Leucocephali plus the segregate genus Kyllingiella. The sixth clade is a well-supported monophyletic clade encompassing all C 4Cyperus s.l. species ('C 4Cyperus'). This study establishes a phylogenetic framework for future studies. © 2011 The Linnean Society of London.