Japan Flora: Stems slender, ascending, branched at base, simple above, 3- to 12-grooved, the central cavity about 1/3 the diameter of the stem or much reduced or absent in small stems; sheaths green with a black border, the teeth 4-10, lanceolate to lanceolate-deltoid, persistent; spikes 5-10 mm. long.
Hokkaido; rare. Sakhalin, Kuriles to N. America, and Europe.