Description from Flora of China
Muhlenbergia ramosa var. curviaristata Ohwi, Acta Phytotax. Geobot. 6: 292. 1937; M. curviaristata var. nipponica Ohwi; M. tenuiflora (Willdenow) Britton, et al. subsp. curvi-aristata (Ohwi) T. Koyama & Kawano.
Plants with creeping scaly rhizomes; rhizomes up to 10 cm, 2–3 mm thick. Culms erect, 60–100 cm tall, ca. 2 mm thick, not branching in upper part, smooth or puberulent below nodes. Leaf sheaths loose, glabrous or scaberulous; leaf blades 8–19 cm × 3–6 mm, flat, scabrid on both surfaces and margins; ligule 0.5–1 mm, apex truncate, lacerate. Panicle 15–35 × 0.5–1.5 cm, effuse or contracted; branches usually two per node, ascending, scabrid. Spikelets lanceolate, 3–3.5 mm, pale purplish; glumes membranous, 1-veined, scabrid on veins, apex acute; lower glume 1.5–2 mm, upper glume 2–2.5 mm; lemma equal to spikelet, 3–3.5 mm, glaucous and variegated with dark gray, lower 1/4 of back pilose; awn 5–10 mm, flexuose or erect, pale or sometimes purplish, scabrid. Anthers ca. 1 mm. Fl. and fr. Jul–Sep. 2n = 40.
Grassy places on mountain slopes, forests, moist ground along roadsides; 900–1400 m. Hebei, Jilin, Liaoning [Japan].