Three new, early diverging Carex (Cariceae, Cyperaceae) lineages from East and Southeast Asia with important evolutionary and biogeographic implications.

Traditional Cariceae and Carex (1966 spp.) classifications recognised five genera (Carex, Cymophyllus, Kobresia, Schoenoxiphium, Uncinia) and four subgenera (Carex, Vignea, Vigneastra, Psyllophora). However, molecular studies have shown that only Carex, divided into five major lineages (the Core Carex, Schoenoxiphium, Core Unispicate, Vignea and Siderostictae Clades), is natural. These studies have also suggested that many early diverging tribal lineages are East Asian in origin, but the sampling of East Asian groups has been poor, and support for relationships within and among major Cariceae clades has been weak. To test deep patterns of relationship in Carex we assembled the longest sequence dataset yet (ITS, ETS 1f, matK, ndhF, rps16; ca. 4400bp) with taxonomic sampling focused on critical East and Southeast Asian Carex sections that have blurred subgeneric limits (Decorae, Graciles, Mundae) or have been at the heart of theories on tribal origins (Hemiscaposae, Indicae, Surculosae, Euprepes, Mapaniifoliae, Hypolytroides). Results indicate that subg. Vigneastra is highly polyphyletic (in five of seven major lineages recognised), and they provide the strongest support yet seen for all previously recognised major Cariceae clades in a single analysis (⩾93% BS). Moreover, results provide strong evidence for three previously unrecognised early diverging East and Southeast Asian lineages: a "Hypolytroides Clade" (sect. Hypolytroides) sister to the Siderostictae Clade, and for a "Dissitiflora Lineage" (sect. Mundae) and a morphologically diverse "Small Core Carex Clade" (sects. Graciles, Decorae, Mapaniifoliae, Euprepes, Indicae) as successive sisters to approximately 1400 species in the Core Carex Clade. Our findings also suggest that morphological diversification may have occurred in clades dominated by Asian species followed by canalization to a narrower range of morphologies in species-rich, cosmopolitan lineages.