Senecio pterophorus is an heterotypic synonym of S. grisebachii : Nomenclatural study of the names, morphological notes, and chorology.

Senecio icoglossusvar.araneosusby Grisebach (nowS. grisebachii) andS. pterophorushave been traditionally recognized as distinct species, although some authors highlighed their morphological affinities and argued a study of the original material to clarify their identities. In this paper, the two names are investigated, the first one (S. icoglossusvar.araneosus) is typified on a specimen preserved at GOET (neotype), while the holotype (preserved at P) was found forS. pterophorus. For the nomenclatural purposes, the namesS. balansae(holotype and isotype, respectively, at K and G),S. icoglossusvar.araneosusby Candolle (lectotype in P, designated in this paper),Senecio pterophorusvar.apterusand var.verus(nom. superfl. et nom illeg., Art. 52.2 of the ICN) andS. pulcher(lectotype and isolectotype at K, designated in this paper) are also discussed. Morphological observations on material from Australia, Europe, South America and South Africa were done. The results show thatS. icoglossusvar.araneosusby Grisebach and Candolle are to be applied to different taxa. The Candolle's name is an heterotypic synonym ofS. pulcher(an endemic South american species). The Grisebach's name is indeed an heterotypic synonym (syn. nov.) ofS. pterophorus, the nameS. pterophorushaving nomenclatural priority. The characters of five out of the seven varieties described forS. grisebachiihave a continuous variability, so their names are to be considered synonyms ofS. pterophorus. The origin of the species is discussed, and two hypotheses are proposed: a “natural origin” (disjuction distribution related to a long-distance dispersal event) and a “recent indtroduction” (alien populations and endemic taxon). Morphological and chorological notes are also provided. [ABSTRACT FROM AUTHOR]