13. Achnatherum nakaii (Honda) Tateoka ex Imzab in Ma et al., Fl. Intramongol. 7: 196. 1983.
朝阳芨芨草 chao yang ji ji cao
Stipa nakaii Honda, Rep. First Sci. Exped. Manchoukuo, Sect. IV, 4: 104. 1936; S. roerichii Keng.
Perennial, densely tufted; roots sometimes coated with sand. Culms erect, 40–60 cm tall, 1–1.2 mm in diam., 2–3-noded. Leaf sheaths smooth or sparsely pubescent, lower longer than internodes; leaf blades setaceous, 10–30 cm, 1–4 mm wide, smooth or scabrid along margins; ligule truncate, 0.5–1 mm, lacerate. Panicle fairly loose, 12–25 cm; branches 2–3 per node, ascending or widely spreading at maturity, scabrid, lower part bare. Spikelets 5–6.5 mm, yellowish green or brownish purple; glumes oblong-lanceolate, subequal or lower glume slightly shorter, 3-veined, puberulous, acute; callus obtuse, ca. 0.5 mm; lemma firm, 4.5–5 mm, densely pubescent; awn persistent, 1–1.5 cm, weakly 1(or 2)-geniculate, scabrid throughout. Anthers 3–4 mm, glabrous or with a few hairs at apex. Fl. and fr. Jul–Sep.
Grassy places on mountain slopes, floodlands; 1200–1700 m. Hebei, Liaoning, Nei Mongol, Shanxi [Mongolia].
This species appears to be a small-spiculate member of the Achnatherum sibiricum-pekinense complex. The type has not been seen.
The combination Achnatherum nakaii has usually been attributed to Tateoka (J. Jap. Bot. 30: 208. 1955), but it was not validly published there because Tateoka made no reference to Honda's basionym.