Molecular Phylogenetic Analyses and Systematics of the Genus Saussurea and Related Genera (Asteraceae, Cardueae)

The phylogenetic relationships of the genus Saussurea DC. and Hemistepta lyrata Bunge were analyzed using the nuclear ribosomal ITS and chloroplast matK gene. Phylogenetic analyses revealed that Saussurea ceratocarpa Decne. of subg. Jurinocera (Baill.) Lipsch. and the species assigned to sect. Elatae Hook.f. of subg. Saussurea were separated from all other members of the genus Saussurea. The species of subgen. Jurinocera and subgen. Saussurea sect. Elatae form a monophyletic unit along with a group including genus Jurinea Cass. The species of subg. Jurinocera and sect. Elatae share 4-5-gonal cypselas and apical pericarpal crowns bearing sharp horns or sharp teeth. The Saussurea s.s. group is comprised of representatives of six sections of the subg. Saussurea and morphologically distinctive subgenera [Amphilaena (Stschegl.) Lipsch., Eriocoryne (DC.) Hook.f, and Theodorea (Cass.) Lipsch.]. Two frigid-adapted forms, the "snowball plants" of subg. Eriocoryne and the "glasshouse plants" of subg. Amphilaena, were confirmed as members of Saussurea s.s. Hemistepta lyrata and Saussurea s.s. show a close sister relationship, which is supported by the pappus dimorphism involving free, short, scabrid outer bristles or tiny outer scales and basally connate in a ring, with much longer, plumose inner bristles.