Very localized and poorly-known seedeater. Mostly known from northeastern Argentina and southern Paraguay, but also a disjunct cluster of records in Bolivia. Might undergo seasonal movements. Males have blackish or dark brown throat and cheek (sometimes extending onto nape and upper breast), gray crown, and unmarked tan underparts. Females are pale sandy-brown overall; note dark bill. Look for pairs or small flocks in open grassy habitats, often mixed with other seedeaters.