Densely caespitose. Stems 5-30 cm, erect; basal sheaths leafless, brown, shining. Leaves equalling or longer than stems, 0.5-1.5(-2) mm wide, canaliculate. Spike solitary, 10-25(-30) x 2-3 mm, with 10-20 spikelets. Terminal spikelet of several male flowers; lateral each with 1 male flower above and 1 female flower below. Glumes brown, with scarious margin. Nut 1.5-2.5(-3) mm, brown, shining.
K. sibirica (Turcz. ex Ledeb.) Boeckeler, Linnaea 39: 7 (1875), differing from K. myosuroides chiefly in having wider spikes with the lateral spikelets each containing 1 male and 2-5 female flowers, has been recorded from the C. Ural at 59° 40' N.. very close to the boundary of Europe.
Dry places; calcicole.