Culms to 4 m tall, to 1.5 cm thick, nodding to pendulous; internodes 8–20 cm, not finely ridged, basally glossy, distally lightly white-pruinose with a very distinct persistent dense brown scurfy ring below node; nodes with slightly raised supra-nodal ridge, sheath scar not raised; branches (2–)3(–4). Culm sheath longer than the internode, to 30 cm, apically narrow, to 3 mm wide, with sparse appressed antrorse setae, external margin ciliate at first; auricles absent; oral setae absent; ligule to 0.5 mm, truncate; blade to 3 cm, narrowly lanceolate, to 3 mm wide, erect, glabrous, deciduous. Leaf sheaths with central ridge, glabrous, not pruinose, margins glabrous; ligule to 1 mm, truncate, ciliate, glabrous, external ligule shortly ciliate; blade large, broad, to 40 cm long, to 8 cm wide, glabrous. 2n = unknown. Named after Ms Hamada, Japanese botanist.
The only species of Indocalamus from Japan, I. hamadae differs from the Chinese species in having stronger branch development, larger stature, and a prominent ridge or keel on the leaf sheaths.