Molecular and morphological data reveal a new species of Sclerorhachis (Compositae, Anthemideae) and the reassessment of another species of the genus

An expanded phylogenetic reconstruction based on the nuclear ribosomal DNA internal transcribed spacer region (nrDNA ITS) in conjunction with a multivariate statistical analysis of morphological characters revealed a new species and the re-acknowledgement of another one in Sclerorhachis (Compositae, Anthemideae). The newly revealed species, Sclerorhachis ferdowsii, has been previously included in the so-called S. platyrachis-complex, but is easily distinguished as an independent species by its rhizomatous root system, sparsely paleate receptacles, coronate and costate achenes, the relatively smaller size of the capitula, and the smaller habit of the whole plant. Additionally, morphological and molecular data corroborated S. paropamisica as a distinct species rather than being conspecific with S. platyrachis. With these newly acknowledged taxa, the number of species in Sclerorhachis is now expanded to eight. A detailed morphological description, an illustration, and distribution maps for S. ferdowsii, along with an identification key for all species of Sclerorhachis, are provided.