Diffuse bamboo with extensively running rhizomes. Culm 3-6 m, dark green; nodes swollen and prominent; internodes obtusely quadrangular in cross section; lower internodes less obviously so; lowest nodes with short indurated adventitious rootlets which become spiny. Culm-sheath to 12 × 8 cm, triangular, tardily deciduous, purple with dark purplish tessellations; auricles and oral bristles 0; sheath-blades very small. Branches spreading widely and ± drooping above, sometimes purplish. Leaf-sheath with long bristles at apex. Leaf-blade 9-24 × 0.7-2 cm, narrow lanceolate or linear-lanceolate, deep green on both surfaces, tessellate, ± drooping.