A molecular phylogeny of the subfamily Arundinoideae (Poaceae) based on sequences of rDNA

Phylogenetic relationships of the whole Poaceae family inferred from the sequence data of rDNA (ITS) support the hypothesis that the arundinoids are monophyletic, not polyphyletic as previously proposed. The ITS sequence phylogeny of 42 arundinoid species demonstrates an early divergence of the Aristideae and three major groupings, corresponding loosely to the tribes Aristideae, Arundineae and Danthonieae. The Arundineae are resolved into two paraphyletic clades. In one clade, Arundo, Monachather, and Dregeochloa are the sister group to Amphipogon and Diplopogon. In the other clade, Phragmites, Molinia, Gynerium, Thysanolaena, Spartochloa, and Cyperochloa are the sister group to Eriachne and Micraira. Arundo is not closely related to Phragmites. The Danthonieae clade, including taxa from Africa, Australia, New Guinea, New Zealand, the South American Cortaderia, and the North American Danthonia, appears to be monophyletic. However, the genus Merxmuellera is polyphyletic.