Overlooked singularity and tiny plants: the F ilago desertorum clade ( G naphalieae, A steraceae)

F ilago desertorum , as traditionally circumscribed, is a species that shows high levels of morphological variation. Previous authors have even suggested that this taxon should represent a heterogeneous assembly of true biological species. A taxonomic revision of the species included in the F ilago desertorum clade was performed, and amplified fragment length polymorphism ( AFLP ) markers were used to explore the phylogenetic relationships among the members of the clade. Three species are recognized in the group, one of which is newly described. A full description of F. castroviejoi sp. nov. , a complete nomenclatural treatment and a key to the species included in the clade are provided. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society , 2015, 179 , 742–754.