Two subspecies recognized:
melanophaius, described as Rallus melanophaius by Vieillot (1819); type locality Paraguay.
Occurs from Venezuela south to Paraguay, Argentina, and Uruguay, except western Amazonia.
See Detailed Description.
oenops, described as Porzana oenops by Sclater and Salvin (1880); type locality Sarayacu, Ecuador.
Similar to nominate melanophaius, but upperparts paler; forecrown and postocular areas rufous or strongly washed with rufous (Blake 1977, Taylor 1998)
Occurs in southeastern Colombia, eastern Ecuador, eastern Peru (except southeastern Peru, where more similar to melanophaius; Schulenberg et al. 2010), and western Brazil (east to Itacoatiara, Amazonas).