Caespitose perennial plant, sometimes provided with short stolons, which emits stems of 60 - 125 cm. The leaves are linear, very ribbed, 20 - 50 cm x 2 - 3 mm, rigid, erect, acute margin, glaucous at the top, and persistent when they die; they are sheathing, and the sheath has a purplish red color when young and then become brown or whitish.