The genus Sorghastrum was studied in Rio Grande do Sul. S. nutans does not occur in the area and was excluded from the flora of the State. The ocurrence of S. nutans (L.) Nash ssp. albescens (Hackel) Burkart was confirmed. Since this taxon shows different morfological characteristics, as compared to S. nutans, it must be considered as a different species. The new taxonomic combination S. albescens (Hackel) Flores is suggested.
Nomenclature; Andropogoneae; Gramineae