Nomenclatural changes in Chenopodium (incl. Rhagodia) (Chenopodiaceae), with considerations on relationships of some Australian taxa and their possible Eurasian relatives

Following recent molecular phylogenetic results, species earlier placed in Rhagodia R.Br. were transferred to Chenopodium L. (Chenopodiaceae). However, three new species-level combinations proposed were later homonyms and thus illegitimate under ICN Art. 53.1. The new name C. wilsonii S.Fuentes, Borsch & Uotila [= C. crassifolium (R.Br.) S.Fuentes & Borsch, comb. illeg.] has been already proposed for one of these species. We propose here two new replacement names, C. robertianum Iamonico & Mosyakin, nom. nov. [≡ R. hastata R.Br. ≡ C. hastatum (R.Br.) S.Fuentes & Borsch, comb. illeg.] and C. benthamii Iamonico & Mosyakin, nom. nov. [≡ R. crassifolia R.Br. var. latifolia Benth. ≡ C. latifolium (Benth.) S.Fuentes & Borsch, comb. illeg.]. One new combination, C.benthamii subsp. rectum (Paul G.Wilson) Iamonico & Mosyakin, comb. nov. [≡ R. latifolia (Benth.) Paul G.Wilson subsp. recta Paul G.Wilson] is also validated. Indications of ‘holotypes’ of R. hastata by Scott and R. crassifolia var. latifolia by Wilson are corrected to lectotypes according to ICN Art. 9.9. Possible relationships and biogeographical links of Australian species earlier placed in Rhagodia, Einadia Raf., and Australian endemic groups of Chenopodium (sections Auricoma Aellen, Desertorum Paul G.Wilson, Rhagodioides Benth. etc.) with Eurasian taxa of Chenopodium (in particular, C. sect. Acuminata Ignatov, C. frutescens C.A.Mey., and newly recognised C. sect. Vulvaria (Standl.) Iamonico & Mosyakin, comb. nov.) are also discussed. Earlier predictions of these possible relationships are emphasised and new predictions are made, which should be tested by molecular phylogenetic and other methods.