Ischaemum aristatum L.

This species usually has awnless or only inconspicuously awned racemes, but occasionally the awns are a little longer and more obvious. Longer awns are weakly associated with a more broadly winged sessile spikelet, and the type of the species name falls within this less frequent variant.

Perennial. Culms loosely tufted, erect or geniculately ascending, 40–80 cm tall, simple or branching, nodes glabrous. Leaf sheaths glabrous or pilose; leaf blades linear-lanceolate, 5–25 × 0.4–1 cm, glabrous or thinly pilose, margins smooth becoming scabrid toward apex, base attenuate or contracted, apex acuminate; ligule 2–3 mm. Racemes terminal, paired, appressed back to back, 4–7 cm; rachis internodes clavate, triquetrous, scabrid or ciliate along outer angle, inner angles glabrous or shortly ciliate. Sessile spikelet oblanceolate to obovate, 5.5–8 × 2–2.3 mm; lower glume leathery with rounded flanks below middle, herbaceous, broader and 2-keeled above, 5–7-veined, keels narrowly to broadly winged, wing margin scabrid; upper lemma awnless or shortly awned; awn well developed or imperfect, up to 1.2 cm. Pedicelled spikelet dorsally compressed, resembling sessile, asymmetrical, 2-keeled, keels winged, one wing incurled. Fl. and fr. Jul–Oct. 2n = 56, 72.

S Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hebei, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Liaoning, Shandong, Taiwan, NE Yunnan, Zhejiang [Japan, Korea, Vietnam].

Open grassy sandy places, often near the sea; 100–1000 m.

Ischaemum crassipes (Steud.) Thell. var. formosanum (Hack.) Nakai, Bot. Mag. Tokyo 33: 2. 1919; Honda, Monog. 355. 1930.