Phylogeny in Artemisia (Asteraceae, Anthemideae) inferred from nuclear ribosomal DNA (ITS) sequences

The internal transcribed spacers (ITS-1 and ITS-2) of nuclear ribosomal DNA were sequenced for 33 populations of 31 species of Artemisia. The sequence data support the monophyly of the genus in its classical, broad sense, inc luding Seriphidium and Oligosporus. Five main clades are defined, correspon ding largely to the four main groups traditionally recognised in the genus: "Artemisia" (s.str.), "Absinthium", "Dracunculus", and "Seriphidium", plus the American "Tridentatae" segregated from the latter, except that "Artemi sia", scattered over four different clades, is in need of a redefinition an d restriction to the A. vulgaris clade. ITS data also support the hypothesi s that the "Tridentatae" and "Seriphidium" are independent groups, and help differentiate the species in the A. herbaalba complex.