Abstract
Taxonomy and nomenclature of several taxa related to Oxybasis glauca (≡ Chenopodium glaucum, Chenopodiaceae) are discussed. New nomenclatural combinations, i.e. O. ambigua (≡ C. ambiguum), O. amurensis (≡ C. amurense), and O. parodii (≡ C. parodii), are validated for three species native to Australasia (mainly Australia and New Zealand), East Asia (Russian Far East), and South America (Argentina), respectively. Information on type specimens is updated; in particular, it is demonstrated that the name Blitum rubrum var. hypoleucum was applied by Spegazzini to two species now recognized as O. parodii and O. macrosperma, but its newly designated lectotype belongs to O. parodii. It is concluded that the worldwide diversity of the O. glauca aggregate remains underestimated and further integral studies are needed for revealing taxonomic and geographic patterns in the group, and for reflecting them in updated taxonomy.