We used nuclear rDNA-sequence data from the internal transcribed spacer (ITS) region to test the monophyly of 'Schoenus' by using maximum parsimony and Bayesian inference. 'Schoenus' is not monophyletic, with strong bootstrap support for most branches and congruence across analyses. nrITS does not resolve terminal taxa fully and, therefore, needs to be used in combination with other lines of evidence to address questions of species limits.