Panicum pachystachys Franchet & Savatier, Enum. Pl. Jap. 2: 594. 1879; Chaetochloa viridis (Linnaeus) Scribner var. pachystachys (Franchet & Savatier) Honda; Setaria pachy-stachys (Franchet & Savatier) Matsumura; S. viridis var. pachy-stachys (Franchet & Savatier) Makino & Nemoto.

Culms usually decumbent at base, much branched, 5–25 cm tall. Leaf sheaths densely tuberculate-pilose in the lower part; leaf blades narrowly lanceolate, stiff, 1.5–5 × 0.2–0.4 cm, glabrous but scabrous on both surfaces. Panicle ovate or elliptic, 1–4 cm; bristles below spikelet 10–25, very dense, green, yellow, or purple, 6–8 mm. Spikelets 2–2.5 mm.

This is a maritime form characterized by its low, branching habit and short, broad, densely bristly panicle.

Sand and pebbles of the seashore. Guangdong, Taiwan [Japan, Korea].