Stems 20-75cm Long, erect, firm, simple, evergreen, 3-8mm Across, shallowly 14-to26-grooved, scaberulous, the ridges with 2 rows of tubercles, the central cavity about2/3 the diameter of the stem; sheaths 5.5-14mm Long, tight, a little longer than broad(3-8mm wide), with a black band below the middle and a black border, the teeth 14-26, the apical portion 3-6mm long, membranous, dark brown, caducous, the basalportion persistent on the sheath; spikes 6-13mm long, sessile. (Korea)