13. Setaria arenaria Kitagawa, Rep. Inst. Sci. Res. Manchoukuo. 4: 77. 1940.
断穗狗尾草 duan sui gou wei cao
Setaria viridis var. sinica Ohwi.
Annual. Culms densely tufted, geniculate at base, slender, 20–100 cm tall, smooth, glabrous. Leaf sheaths loose, lower papillose-pubescent, upper glabrous, margins and mouth ciliate; leaf blades narrowly lanceolate, thin, 5–15 × 0.2–0.7 cm, glabrous, scabrous on both surfaces, base subrounded, apex long acuminate. Panicle narrowly cylindrical, commonly interrupted below, 2–9 × 0.5–0.8 cm; branchlets with several spikelets, these subtended by 1–4 bristles; axis pilose, rarely glabrous; bristles green or purple, 2–8 mm. Spikelets narrowly elliptic, 2.5–3 mm, acute; lower glume ovate, thinly papery, ca. 1/2 as long as spikelet, acuminate; upper glume as long as spikelet or slightly shorter; lower floret neuter, lemma equal to spikelet, 5-veined; lower palea small, narrowly lanceolate; upper lemma pale green or yellowish, finely rugose, acuminate. Fl. and fr. Jul–Sep.
* Sandy places; 1000–1300 m. Hebei, Heilongjiang, Nei Mongol, Shanxi.