Included in Scirpus in Michigan Flora.

1. Styles 3-cleft; achenes distinctly 3-angled, 4-5 mm long; involucres mostly with 3-5 well-developed bracts; perianth bristles strong, distinctly retrorse-barbed.

B. fluviatilis

1. Styles 2-cleft; achenes biconvex, 3-4 mm long; involucre with 2 well-developed bracts; perianth bristles weak, scarcely half as long as achene, obscurely barbed.

B. maritimus