A gray-green plant with long creeping rhizomes, giving long underground shoots. The stems are smooth, or slightly rough at the top, 15-40 cm tall, at the base dressed with purple-brown, non-splitting fibrous leafless sheaths. The leaves are keeled, 2.5-5 mm wide, with a back-wrapped edge, rough, bent from the stem, shorter than the stem. It bears fruit in May—June.