Rhaponticum Ludwig. Russian Knapweed.
A genus of about 26 species, herbs, native of Eurasia. Hidalgo et al. (2006) showed that Acroptilon is best merged into Rhaponticum.
Ref: Hidalgo et al. (2006); Keil (2006i) In Flora of North America Editorial Committee (2006a); Susanna & Garcia-Jacas In Kadereit & Jeffrey (2007). Show full citations.