IPNI lists the name "Jacobaea arenaria" as invalid, as the attempt to publish it (http://old.ssbg.asu.ru/turcz/p58-63.pdf) failed to cite the location of publication of the "basionym" (https://ipni.org/n/20004937-1). Even were this not the case, though, the publication acknowledges that Senecio arenarius M.Bieb. is an illegitimate later homonym of Senecio arenarius Thunb. As such, it cannot act as a basionym, and the name "Jacobaea arenaria" would be treated as a replacement name. However, the authors listed Senecio grandidentatus in synonymy, and according to Article 11.4, should have taken the epithet from this name rather than publishing a replacement name. This combination was subsequently published, and is the correct name for this taxon.