Notes on the identity of Scorzonera picridioides and Scorzonera paradoxa (Asteraceae)

Abstract

Due to confusion in the identity of Scorzonera paradoxa and Scorzonera picridioides and their inconsistent taxonomic treatments in previous literature and regional floras, we performed a detailed bibliographic and morphological revision of both species in order to elucidate their taxonomic identities. Examination of specimens in the field or various herbaria and critical surveys of type specimens and previous literature represented that S. paradoxa and S. papposa possessed a considerable overlap in the morphology and geographic distribution, and consequently, S. paradoxa was confirmed as a synonym of S. papposa. We also found that S. papposa and S. paradoxa were morphologically different from S. picridioides in plant height, shape of basal leaves, color of florets, color of anther tube, and pappus bristles, thus, S. picridioides was re-established as an independent species. In accordance with a recent taxonomic revision of subtribe Scorzonerinae that split Scorzonera s. l. into independent genera and placed S. papposa in genus Pseudopodospermum, we proposed the placement of S. picridioides in Pseudopodospermum, and provided an updated morphological description and geographic distribution notes for Pseudopodospermum papposum and Pseudopodospermum picridioides.