True rushes are easily distinguished from grasses and sedges, with which they are sometimes confused, by the presence of a true perianth of 6 tepals and a 3-many-seeded capsule rather than a 1-seeded grain or achene.

1. Foliage completely glabrous; capsules usually many-seeded.

Juncus

1. Foliage ± hairy, at least toward summit of sheaths; capsules 3-seeded.

Luzula