Thicket-forming with rhizomes shortly creeping. Culm usually 4-6 m × 1.3-2 cm diam. below, upper internodes flattened, glaucous-white when young, becoming olive-green and often reddish brown on exposed parts, erect, semi-fastigiate. Culm-sheath glabrous, to c. 20 × 8 cm on large culms, abaxially greenish, or ± entirely green on small peripheral culms, adaxially shining light purple; ligule c. 2 mm, ciliate; oral bristles 0; sheath-blade 4-11 cm, narrow linear. Leaf-sheath with oral bristles. Ligule truncate. Leaf-blade 8-18-(21) × 1-2-(2.3) cm, linear-lanceolate, finely long acuminate. Spikes 3-7 cm, purplish. Lemma 1.8-2.2 cm, aristate. Lodicules 4-5 mm, ciliate. Anthers long-exserted, 7-8 mm.