The paraphyly of Cortaderia (Danthonioideae; Poaceae):: Evidence from morphology and chloroplast and nuclear DNA sequence data

The genus Cortaderia Stapf comprises approximately 24 species occurring in South America, New Zealand, and New Guinea. Cortaderia is placed in the subfamily Dantlionioideae. Several species in the genus are known to be gynodioecious. a feature unusual for the subfamily. The genus has been divided into four sections, two of which are monotypic. This study Utilizes nrDNA sequence data from the ITS region and the grass-specific insert in the chloroplast rpoC2 gene to elucidate the relationships of 15 species of the genus, including the anomalous Cortaderia archboldii (Hitclic.) Connor & Edgar. Results suggest that the genus is not monophyletic, an(] there are two clades that correspond to Continental areas. The South American species of Cortaderia (including Lamprothyrsus Pilg.) form one clade, while the Australasian species form a second clade. Within Cortaderia s. str., section Bifida is potyphyletic, while section Cortaderia is monophyletic and sister to Lamprothyrsus. Cortaderia archboldii shows no immediate affinity with either of these two clades, but data indicate a possible relationship with Danthonia DC.